JP3244256B2 - Mobile communication area expansion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric / optical converter and an optical / electrical converter for a base station that uses TDD (Time Division Duplexing) for a wireless access system such as PHS and shares an antenna for transmission and reception. An optical interface device composed of a converter is connected, and this optical interface device is connected to a radio base station device that transmits and receives radio waves to and from a mobile terminal by an optical fiber, thereby separating the radio communication area from the base station. The present invention relates to a wireless communication area expansion device in a mobile communication system in which a base station and a mobile terminal communicate with each other by extending to an installation location of a wireless base station device.

[0002]

2. Description of the Related Art In recent years, in a cellular system, a booster system using an optical fiber has been developed for the insensitive delay in an underground mall or the like. FIG. 5 shows a configuration diagram of an optical fiber booster system used in a cellular system. Although not shown in the figure via the interface 12, the cellular base station 11 is connected to a mobile communication exchange via, for example, a wired transmission path, and a downstream signal from the mobile communication exchange is converted into a high-frequency signal by the modulator 13, and furthermore, The signal is amplified by the amplifier 14 and converted into an optical signal by the electric / optical converter 16 of the optical interface device 15, and the optical signal is input to one end of the optical fiber 17. The optical fiber 17 is extended to, for example, a wireless base station device 18 provided in an underground mall, and an optical / electrical converter 19 of the wireless base station device 18 converts an optical signal from the optical fiber 17 into an electric signal. Transmission amplifier 2
1, passes through the transmission bandpass filter 22, and further passes through the transmission / reception separation circulator 23 from the antenna 24, for example, a wireless communication zone (cell) 25 in an underground shopping mall
Is emitted as radio waves.

A mobile terminal 26 moving in a wireless communication zone 25 can transmit and receive radio waves to and from the radio base station apparatus 18.
, Passed through a circulator 23, further passes through a reception bandpass filter 27, is amplified by a reception amplifier 28, and is converted into an optical signal by an electric / optical converter 29. The optical signal is transmitted through the optical fiber 31 to the optical /
The electric signal is transmitted to an electric converter 32, where it is converted into an electric signal. The electric signal is amplified by an amplifier 33 in the base station 11, and is demodulated by a demodulator 34. Transmitted to

In a cellular system, an FDD (Frequenque) using different frequencies for transmission and reception signals as a radio access system.
cy Division Duplexing: Simultaneous frequency division transmission and reception), so there is no need to switch between transmission and reception. Therefore,
As shown in FIG. 5, the antenna terminals 11a of the base station 11,
The optical fiber booster system can be easily realized by connecting the optical interface device 15 to 11b.

[0005]

On the other hand, in PHS, from the viewpoint of frequency utilization efficiency, TDD is used for the radio access system.
(Time Division Duplexing). Figure 6 shows PH
The configuration of the S base station 41 is shown with the same reference numerals assigned to parts corresponding to those in FIG. The movable terminal of the antenna selection switch 42 is connected to the output side of the amplifier 14, and the fixed terminals 42a and 42b of the antenna selection switch 42 are connected to the fixed terminals 43a and 44a of the transmission / reception changeover switches 43 and 44, respectively. , 44 are connected to antennas 45, 46 through antenna terminals 41a, 41b. Fixed terminal 43 of transmission / reception changeover switches 43 and 44
b and 44b are connected to demodulators 34 and 48 through amplifiers 33 and 47, respectively, and the output side of the demodulator 48 is connected to the interface 12.

This device has a transmission / reception diversity function.
The transmission is performed by switching 46. In the TDD system, since the antenna is shared for transmission and reception, the transmission / reception switch 43,
Transmission / reception switching is performed by 44. Therefore, when the optical fiber booster system is applied to the PHS base station, simply connecting the antenna terminal of the base station to the optical interface device as in the cellular system shown in FIG.
1a and 11b alternately switch between transmitting a transmission signal and receiving a reception signal, so that both the electrical / optical converter 16 and the optical / electrical converter 32 transmit the transmission signal. It is necessary to perform transmission and reception of a received signal, and it is difficult to perform normal communication.

[0007] It is an object of the present invention to connect a base station operating in the TDD system to a remote radio base station apparatus via an optical fiber, thereby expanding a service area of the base station. It is to provide a device.

[0008]

According to the first aspect of the present invention, the radio base station apparatus is provided with the same antenna selection switch as the base station, two transmission / reception changeover switches, and two antennas, and similarly connected. Then, similarly, the antenna selection control and the transmission / reception switching control are performed, and one of the reception signals from the two antennas is converted into a frequency band by a frequency conversion circuit.
The signal is combined with the other received signal and supplied to the electric / optical converter.
The radio base station device requires only one optical / electrical converter and only one electric / optical converter. The converted output signal from the optical / electrical converter is divided into two parts by the optical interface device. The received signal that is not frequency-converted is extracted by a band-pass filter, the other is returned to the frequency before conversion by the frequency conversion circuit, and supplied to one antenna terminal of the base station. The input side of the electro-optical converter and the output side of the band-pass filter are switched and connected. The transmission / reception switches of the base station, the optical interface device, and the wireless base station device perform switching control in synchronization with each other. However, it is natural in design to provide a time lag according to the transmission delay.

According to the second aspect of the present invention, n base stations are provided, and n transmission / reception switches of the optical interface device are provided in correspondence with the base stations. The output is converted by a conversion circuit, these converted outputs are combined and supplied to an optical / electrical converter, and the output of the band-pass filter is divided into n output signals, supplied to n transmission / reception switches, and subjected to frequency conversion. The output of the circuit is distributed to n and supplied to the second antenna terminals of the n base stations. In the radio base station, the output of the optical / electrical converter is distributed to n, and the signal frequency is returned to the signal frequency before the conversion of the n frequency converters in the optical interface device by the n frequency converters. , And the output signals of one fixed terminal of these n antenna selection switches are combined and supplied to one transmission / reception switch, and the output signal of the other fixed terminal is combined. To the other transmission / reception changeover switch.

According to a fourth aspect of the present invention, in the radio base station apparatus, the uplink received signal according to the second aspect of the present invention is converted into n different signals at different bands and at different frequencies. After being converted by the circuit, the signal is combined and transmitted as an optical signal to the base station, converted into an electric signal by the optical interface device, distributed to 2n, returned to the original frequency by 2n frequency conversion circuits, and corresponding to one antenna The n converted outputs are supplied to the n transmission / reception changeover switches, and the n converted outputs corresponding to the other antenna are supplied to the second antenna terminals of the n base stations.

According to the third aspect of the present invention, the diversity operation is omitted, and the base station is fixed so that both the antenna selection switch and the two transmission / reception changeover switches constitute one transmission system and one reception system. In the wireless base station, the output side of the optical / electrical converter and the input side of the electrical / optical converter are alternately connected to one antenna by a transmission / reception switch.

[0012]

FIG. 1 shows an embodiment of the first aspect of the present invention, in which parts corresponding to those in FIGS. 5 and 6 are denoted by the same reference numerals. The base station 41 uses the TDD wireless access, and has the same configuration as that of a normal PHS base station, for example, that is, the base station 41 has the same configuration as that shown in FIG. An optical interface device 51 is connected to antenna terminals 41a and 41b of the base station 41.
The wireless base station device 52 is connected to the mobile terminal 26 moving in the mobile communication zone (cell) 25 and transmits and receives wireless radio waves to and from the mobile base station device 52 through the mobile communication terminals 7 and 31.

In the base station 41, an antenna selection switch 42
Is fixedly connected to the fixed terminal 43a of the transmission / reception switch 43. In the optical interface device 51, a transmission / reception switch 53 is provided, the movable terminal of which is connected to the antenna terminal 41a of the base station 41, and the fixed terminal 53a is connected to the electric / optical converter (referred to as E / O) 16. The output signal of the optical / electrical converter (hereinafter referred to as O / E) 32 is supplied to a splitter 54.
, One of which is selected by the band-pass filter 55 for the uplink reception radio frequency of the radio base station apparatus 52 and supplied to the fixed terminal 53 b of the transmission / reception switch 53. The other distributed output signal of the distributor 54 is returned by the frequency conversion circuit 56 to the state before the frequency conversion in the wireless base station device 52 and supplied to the antenna terminal 41b of the base station 41.

In the radio base station apparatus 52, the antenna selection switch 42 and the transmission / reception switch 43, 44 of the base station 41 are provided.
Similarly, the antenna selection switch 57 and the transmission / reception changeover switches 58 and 59 are provided, and the connection is made in the same manner as the base station 41. The movable terminal of the antenna selection switch 57 is connected to the output side of the transmission amplifier 21, the movable terminals of the transmission / reception changeover switches 57 and 58 are connected to the antennas 45 and 46, and the fixed terminals 58b and 59b are connected to the reception amplifiers 28 and 61, respectively. Is connected to the input side. Receiver amplifier 61
Is converted by a frequency conversion circuit 62 into a signal of a frequency other than the frequency band used by the mobile communication, and the frequency converted output is combined with the output signal of the receiving amplifier 28 by a coupler 63 to form an electric / optical converter. (Referred to as E / O) 29.

All transmission / reception changeover switches 43, 44, 5
The switching of the switches 3, 58, 59 is controlled synchronously, and the antenna selection switches 53, 57 are also switched synchronously. However, in actual operation, a time difference corresponding to the transmission delay between these switches is provided. On the downlink,
The output signal of the modulator 13 in the base station 41 is
After being amplified at 4, the signal is input from the switch 42 to the terminal 43a of the switch 43. The switch 43 is connected to the terminal 43 a at the time of transmission, and a wireless electric signal is input from the switch 43 to the switch 53 in the optical interface device 51. The switch 53 is connected to the terminal 53a at the time of transmission, and the output signal of the terminal 53a is E /
Input to O16. As a result, the wireless electric signal is converted into an optical signal, and the wireless base station 5
2 is input to the O / E 19. The optical signal is converted into a wireless electric signal by the O / E 19, amplified by the amplifier 21, and then input to the antenna selection switch 57. The antenna selection switch 57 is controlled by a control signal from the base station 41 (not shown) and is connected to the transmission / reception changeover switches 58 and 59, and the radio electric signal is input to the antenna 45 or 46 through the transmission / reception changeover switch 58 or 59. The signal is transmitted from the antenna 45 or 46 to the mobile terminal 26.
The transmission / reception switches 58 and 59 perform transmission / reception switching control according to a control signal from a base station (not shown).

In the uplink, a transmission signal from mobile terminal 25 is transmitted to antennas 45 and 46 of radio base station apparatus 52.
And are input to the amplifiers 28 and 61 via the transmission / reception switches 58 and 59, respectively. The output signal of the amplifier 61 is converted by the frequency conversion circuit 62 into a frequency band that does not overlap with the entire signal frequency band allocated to the system in use, and then combined with the output signal of the amplifier 28 by the combiner 63. The output signal of the coupler 63 is converted into an optical signal by the E / O 29 and then transmitted to the optical interface device 51 via the optical fiber 31. The optical signal from the wireless base station device 52 is transmitted to the optical interface device 5
1 is converted to a wireless electric signal by the O / E 32 in the
4 is input. The output signal of the divider 54 is divided into two parts, a bandpass filter 55 and a frequency conversion circuit 56.
The bandpass filter 55 extracts the received signal of the antenna 45 and inputs the signal to the terminal 53 b of the switch 53. The switch 53 is connected to the terminal 53b at the time of reception, and is input from the terminal 53b to the switch 43 in the base station 41. In the frequency conversion circuit 56, the signal received by the antenna 46 is re-converted to the input frequency of the frequency conversion circuit 62 in the wireless base station device 52, extracted, and input to the switch 44 in the base station 41. Switch 4 in base station 41
3 and 44 are terminals 43b and 44b at the time of reception timing.
, And the wireless electric signal is transmitted to the switches 43 and 4
4 are input to the amplifiers 33 and 47, respectively.
After being amplified at 3, 34, they are input to demodulators 34, 48, respectively.

As described above, the TDD two-way communication is performed between the base station 41 and the mobile terminal 26, and the base station 41
Will provide services for wireless zones 25
This can be done via an optical fiber. Claim 3 in FIG.
In the embodiment of the present invention, parts corresponding to those in FIG. 1 are denoted by the same reference numerals. The difference from the embodiment of FIG. 1 is that in this configuration, transmission / reception diversity is not performed, and no signal is input to the amplifier 33 and the demodulator 34 in the base station 41. The transmission / reception changeover switches 43 and 44 are fixed terminals 43a and 44, respectively.
b is fixedly connected. In the optical interface device 51, only the E / O 16 and the O / E 32 are provided, and these are connected to the antenna terminals 41a and 41b, respectively.
In the wireless base station device 52, only one antenna 45 is provided, and the antenna 45 is switched and connected to the amplifiers 21 and 28 by a transmission / reception switch 57.

In the downlink, the output signal of the modulator 13 in the base station 41 is amplified by the transmission amplifier 14 and then, through the switch 43, the E / O of the optical interface device 51.
16 is input. The wireless electric signal is converted into an optical signal by the E / O 16 and is transmitted through the optical fiber 17 to the wireless base station device 5.
2 is input to the O / E 19. The optical signal is converted into a wireless electric signal by the O / E 19, amplified by the amplifier 21, input to the antenna 45 via the transmission / reception switch 57, and transmitted from the antenna 45 to the mobile terminal 26.

In the uplink, a transmission signal from the mobile terminal 26 is received by the antenna 45 of the radio base station device 52 and input to the amplifier 28 via the transmission / reception switch 57. The output signal of the amplifier 28 is converted into an optical signal by the E / O 29 and then transmitted to the optical interface device 51 via the optical fiber 31. The optical signal from the wireless base station device 52 is converted into a wireless electric signal by the O / E 32 in the optical interface device 51 and transmitted to the switch 44 in the base station 41. The switch 44 is fixedly connected to the terminal 44b, and the wireless electric signal is input from the switch 44 to the amplifier 47, amplified by the amplifier 47, and then input to the demodulator 48.

For example, in PHS, only three channels can be processed in the base station. That is, wireless zone 2
5 cannot communicate with four or more of the mobile terminals 26 at the same time. When the traffic in the wireless zone 25 is large, it is necessary to provide a plurality of base stations and synchronize them for operation. FIG. 3 shows an embodiment to which the present invention (the invention of claim 2) is applied in such a case. 3, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. N base stations 4 having the same configuration as base station 41 in FIG.
₁ 1 ... 41 _n is provided. When n base stations are provided in the configuration shown in FIG. 1 based on the provision of n base stations, the same reference numerals as in FIG. That is, in the base station, each symbol of each part in FIG. 1 has a suffix of 1 or n. In the optical interface device 51, n transmission / reception switches 53 ₁ ... 53 _n
Is provided, the movable terminal being connected to a corresponding one of the base station 41 ₁ ... 41 _n, the fixed terminals 53a ₁ ... 53a _n are connected to the coupler 65 through the frequency conversion circuit 64 ₁ ... 64 _n, coupler 65 Is connected to the input side of the E / O 16. The output side of the band-pass filter 55 is connected to a distributor 66.
And its n-distribution output terminal is connected to a transmission / reception switch 53.
They are respectively connected to the ₁ ... 53 _n fixed terminals 53b ₁ ... 53b _n of. Output side of the frequency converting circuit 56 is connected to the distributor 67, the n distribution output terminal is connected to the antenna terminal 41b ₁ ... 41b _n of the base station 41 ₁ ... 41 _n.

In the radio base station apparatus 52, the output side of the O / E 19 is connected to a distributor 68, and its n distribution output terminals are connected to frequency conversion circuits 69 _{1 to} 69 _n , respectively. is connected to the movable terminal of the antenna selection switch 57 ₁ ... 57 _n through ₁ ... 21 _n. Antenna selection switch 57 ₁ ~57 _n of fixed terminals 57a ₁ ...
57a _n are connected to the combiner 71, the output side of the coupler 71 is connected to a fixed terminal 58a of the transmission and reception change-over switch 58. Antenna selection switches 57 ₁ ... 57 _n fixed terminals 5
7b ₁ ... 57b _n are connected to the combiner 72.
Is connected to the fixed terminal 59a of the transmission / reception switch 59. Other configurations are the same as those in FIG.

In the downlink, the base station 41₁… 41_n
Switch 43₁… 43_nThe output signal of the movable terminal
Switch 53 in interface device 51₁... 53_nNiso
Each is entered. Switch 53₁... 53_nIs Thailand
Terminal 53a₁... 53a_nConnected to
Terminal 53a₁... 53a_nTo frequency conversion circuit 64 ₁
... 64_nRespectively. Wireless electrical signal is frequency
Conversion circuit 64₁... 64 _nUsed in this mobile communication system.
Frequency band that does not overlap with the signal frequency band used, and
The signals are converted into signals having mutually different frequencies. frequency
Number conversion circuit 64 ₁... 64_nThe output signal of
After being combined, it is converted into an optical signal by the E / O16,
The data is transmitted to the station device 52. In the wireless base station device 52
The wireless electric signal output from the O / E 19 is
8 and the frequency conversion circuit 69₁… 69_nEnter in
Is done. The wireless electric signal is transmitted to the frequency conversion circuit 69.₁… 69_n
The frequency conversion circuit 64 in the optical interface device 51
₁... 64_nInput signal frequency.
After that, it is extracted for each wave,₁…
21_nIs input to These amplifiers 21₁… 21_nIncrease
The width output is combined by the coupler 71 and the radio wave is output from the antenna 45.
, Or combined by a combiner 72,
The light is radiated from the tenor 46 as a radio wave.

[0023] In the uplink, the received signal of the band-pass filter 55 in the antenna 45 of the optical interface device 51 is extracted, after being n distributed by the distributor 66, the base station 41 through the switches 53 ₁ ... 53 _n to ₁ ... 41
_n antenna terminals 41a ₁ ... 41a _n .
The output signal of the frequency converting circuit 56, after being n distributed by the distributor 67, the base station 41 ₁ ... 41 _n of the antenna terminal 41b
₁ ... 41b _n are respectively input.

FIG. 4 shows an embodiment of the present invention. This embodiment is a case where a plurality of base stations are used as in the embodiment shown in FIG. 3. However, the difference from FIG. 3 is that the uplink signal also corresponds to each of n base stations. 3 in that the frequency band and the frequency are converted to be different from each other and the optical fiber 31 is transmitted. That is, the reception amplification output from the antenna 45 is divided into n by the divider 81 and the frequency conversion circuits 82 ₁ .
2 is supplied to the _n, receives amplified output from the antenna 46 is a distributor 83 with n distributed by the frequency conversion circuit 84 ₁ ... 84 _n
Supplied to The converted output signals of the frequency conversion circuits 82 _{1 to} 82 _n have different frequencies from each other.
The converted output signals of 4 ₁ ... 84 _n also have different frequencies,
These n converted output signals are in a frequency band outside the frequency band used in the mobile communication system. Each output signal of the frequency converting circuit _{82 1 ... 82 n, 84 1} ... 84 n is supplied are combined in combiner 85 to the E / O29.

In the optical interface device 51, the O / E 32
Output electric signal is distributed 2n by the distributor 86, and its 35
N-number of distribution output of the input to the frequency conversion circuit 87 ₁ ... 87 _n, the frequency converting circuit 82 ₁ ... 82 _n input signals of the same frequency of the signal of the radio base station device 52, i.e. the received signal of the antenna 45 is converted into and supplied to the fixed terminal 53b ₁ ... 53b _n of reception switching switches 53 ₁ ... 53 _n. The other n distributed outputs of the distributor 86 are supplied to frequency conversion circuits 88 _{1 to} 88 _n , respectively, and are the same as the input signals of the frequency conversion circuits 84 _{1 to} 84 _n of the radio base station apparatus 52, that is, the received signals of the antenna 46. base station 41 are converted to the frequency of the signal ₁ ... 41 _n antenna terminal 41b ₁ ... 4 of the
They are respectively supplied to 1b _n.

In the downlink, the base stations 41 ₁ ... 41 _n
The output signal of the switch 43 ₁ ... 43 _n of the inner is inputted to the frequency converter 64 ₁ ... 64 _n of the optical interface device 51. In the frequency conversion circuits 64 ₁ ... 64 _n , the radio electric signals are frequency-converted so that they do not overlap with each other the signal frequency band used by the mobile communication system, and do not interfere with each other in intermodulation distortion and harmonic distortion. , And a coupler 65.

In the uplink, antennas 45 and 4
Reception signal 6 is n distributed respectively distributor 81 and 83, are input to the frequency conversion circuit 82 ₁ ... 82 _n and the frequency converting circuit 84 ₁ ... 84 _n. Respectively, in the frequency converting circuit _{82 1 ... 82 n, 84 1} ... 84 n, the radio electric signal does not overlap the use signal frequency band of the mobile communication system, and intermodulation distortion with each other, the frequency arrangement of the harmonic distortion does not interfere After the frequency conversion, the combiner 85
Are combined. The output signal of the coupler 85 is converted into an optical signal by the E / O 29, and is input to the O / E 32 in the optical interface device 51 via the optical fiber 31. O / E3
Radio signal output from 2 is input to the distributor 86, is 2n distributed to the frequency converting circuit _{87 1 ... 87 n, 88 1} ... 88 n. Frequency conversion circuits 87 ₁ ... 87 _n , 88 ₁ ... 8
In _8n , the frequency of the input signal is converted into the frequency band of the radio section, that is, the frequency band used between the mobile terminal 26 and the radio base station apparatus 52, and is output for each wave. The output signal of the frequency converting circuit 87 ₁ ... 87 _n to the terminal 53b ₁ ... 53b _n switches 53 ₁ ... 53 _n, the output signal of the frequency converting circuit 88 ₁ ... 88 _n is a base station 41 ₁
Each of which is transmitted to the switch 44 ₁ ... 44 _n within ... 41 _n.

As described above, the frequency conversion circuit 64₁… 6
4_n, 82₁… 82_n, 84₁… 84_nIn each other
Frequency allocation so that modulation distortion and harmonic distortion do not interfere
Is below the frequency band used by the mobile communication system.
Channel frequency, channel spacing, upper frequency limit,
From the frequency of the input channel and the third harmonic distortion
Frequency allocation conditions to avoid interference and avoid interference of harmonic distortion
Frequency allocation conditions can be easily determined and these conditions
May be determined at the same time. for that reason
Supply to each frequency conversion circuit according to the transmission channel frequency
Need to change the local signal frequency
Is a frequency synthesizer as its local signal generation means.
Is used. Therefore, the frequency conversion circuit 69₁… 6
9_n, 82₁… 82_n, 84₁… 84_nThen a local signal
A frequency synthesizer is used as a livestock. On the other hand,
Wave number conversion circuit 64₁... 64_n, 87₁… 87_n, 88₁
… 88 _nThe local signal generator has a fixed frequency
It may output a signal. That is, the frequency conversion circuit 64
₁... 64_nConverts the input signal to a fixed frequency band.
Conversion and frequency conversion circuit 87₁… 87_n, 88₁… 88
_nThen, the frequency conversion circuit 82₁… 82_n, 84₁… 84
_nOne of the fixed frequency radio signals output from
Is converted into the frequency band of the wireless section.

[0029]

As described above, according to the present invention, a base station sharing an antenna for transmission / reception and a plurality of mobile terminals are connected via an optical interface device and a radio base station device using TDD as a radio access system. A communication method for connecting an optical interface device and a wireless base station device with an optical fiber can be realized by controlling terminal connections of an antenna selection switch and a transmission / reception switch in the base station. Further, a conventional base station can be used as it is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an embodiment of the invention of claim 3;

FIG. 3 is a block diagram showing an embodiment of the invention of claim 2;

FIG. 4 is a block diagram showing an embodiment of the invention of claim 4;

FIG. 5 is a block diagram showing a wireless zone extension device using an optical fiber booster system in a conventional cellular system.

FIG. 6 is a block diagram showing a configuration of a conventional PHS base station.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H04B 10/14 (56) References JP-A-5-30020 (JP, A) JP-A-5-102894 (JP, A) JP-A-5-252559 (JP, A) JP-A-5-122110 (JP, A) JP-A-5-252088 (JP, A) JP-A-6-189364 (JP, A) (58) Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38 H04B ⁷ /02-7/12

Claims (4)

(57) [Claims] 1. A mobile communication system in which a base station is connected to a wireless base station device distant from the base station via an optical interface device, and the base station communicates with a mobile terminal via the wireless base station device. In the area extension device, the base station has a transmission antenna selection switch connected to an output side of a modulator, and a first fixed terminal of the transmission antenna selection switch and an input side of the first demodulator are connected to each other by a first transmission / reception switch. 1 antenna terminal, and the second fixed terminal of the transmission antenna selection switch and the input side of the second demodulator are switched and connected to the second antenna terminal by a second transmission / reception switch, and the TDD (Time Div
an optical / optical converter for converting an electric signal to an optical signal, an optical / electrical converter for converting an optical signal to an electric signal, and the optical A band-pass filter for extracting a signal of a predetermined band from the electric signal from the electric converter, and a movable terminal of the second transmission / reception switch by converting the output electric signal of the optical / electric converter into a signal of a predetermined frequency. And a transmission / reception switch for switching and connecting a movable terminal of the first transmission / reception switch to an input side of the electric / optical converter and an output side of the bandpass filter. An optical / electrical converter for converting an optical signal from the electric / optical converter into an electric signal; an antenna selection switch connected to an output side of the optical / electrical converter; First and second antennas for transmitting and receiving radio waves to and from a first fixed terminal of the antenna selection switch or an input side of a first receiving amplifier for connecting the first antenna, and a first transmission / reception changeover switch; A second transmission / reception changeover switch for switchingly connecting a second antenna to a second fixed terminal of the antenna selection switch or an input side of a second reception amplifier, and an output signal of the second reception amplifier is connected to the optical interface device. A frequency conversion circuit that performs frequency conversion to the same frequency as the frequency of the electric signal supplied to the frequency conversion circuit, and an output signal of the frequency conversion circuit,
An electrical / optical converter for converting an output signal of the first receiving amplifier into an optical signal and supplying the optical signal to the optical / electrical signal converting circuit in the optical interface device, wherein the transmitting antenna selecting switch in the base station is provided. Is connected to a first fixed terminal of the first transmission / reception switch, and the first and second transmission / reception switches in the base station, the transmission / reception switch in the optical interface device, and the wireless base station device The first and second transmission / reception changeover switches,
A mobile communication area expansion device, which is switched synchronously to enable two-way communication. 2. The number of the base stations is n (n is an integer of 2 or more).
The optical interface device is provided with n transmission / reception changeover switches, and movable terminals of the transmission / reception changeover switches are connected to movable terminals of the first changeover switches of the n base stations, respectively. The first fixed terminals of the n transmission / reception changeover switches respectively shift the electric signal in the frequency band and convert the signals into signals having different frequencies from each other. A combiner for combining each output signal and supplying the combined signal to the electric / optical converter, and distributing the output of the bandpass filter to n;
A first distributor for supplying the second fixed terminals of the n transmission / reception changeover switches to a second fixed terminal; and a first distributor for dividing the output signal of the frequency conversion circuit into n and supplying the output signals to the second antenna terminals of the n base stations. The radio base station apparatus, wherein the antenna selection switch is n.
And n distributors for n-distributing the output electric signal of the optical / electrical converter, and n distributed outputs of the distributor are supplied, respectively, for the n frequency conversion circuits in the optical interface device. An n number of frequency conversion circuits that convert to a signal of a frequency before conversion and supply the signals to the movable terminals of the n antenna selection switches, respectively, and output signals of the first fixed terminals of the n antenna selection switches are combined. To supply a signal to the first fixed terminal of the first transmission / reception changeover switch.
And a second coupler for combining output signals of the second fixed terminals of the n antenna selection switches and supplying the combined signal to a first fixed terminal of the second transmission / reception changeover switch. Item 2. The mobile communication area expansion device according to Item 1. 3. Mobile communication in which a base station is connected to a radio base station apparatus distant from the base station via an optical interface apparatus, and the base station communicates with a mobile terminal via the radio base station apparatus. In the area extension device, the base station has a transmission antenna selection switch connected to an output side of a modulator, and a first fixed terminal of the transmission antenna selection switch and an input side of the first demodulator are connected to each other by a first transmission / reception switch. 1 antenna terminal, and the second fixed terminal of the transmission antenna selection switch and the input side of the second demodulator are switched and connected to the second antenna terminal by a second transmission / reception switch, and the TDD (Time Div
ision Duplexing: time-division simultaneous transmission / reception), an electric / optical converter for converting an electric signal from a first antenna terminal of the base station into an optical signal, An optical / electrical converter for converting an optical signal into an electric signal; an optical / electrical converter for converting an optical signal from the optical interface device into an electric signal; An electric / optical converter for converting the optical signal into an optical / electrical converter in the optical interface device, an antenna for transmitting / receiving a radio wave to / from the mobile terminal, and connecting the antenna to an output side of the optical / electrical converter or A transmission / reception switch for switching connection to an input side of the electric / optical converter, wherein a transmission antenna selection switch in the base station is fixed to a first fixed terminal of the first transmission / reception switch. The first transmission / reception changeover switch has a first fixed terminal fixedly connected to a first antenna terminal, and the second transmission / reception changeover switch has a second fixed terminal fixedly connected to a second antenna terminal. The mobile communication area expansion device, wherein the transmission / reception changeover switch in the wireless base station device is controlled so as to enable two-way communication. 4. Mobile communication in which a base station is connected via an optical interface device to a radio base station device distant from said base station, and said base station communicates with a mobile terminal via said radio base station device. In the area extension device, the base station has a transmission antenna selection switch connected to an output side of a modulator, and a first fixed terminal of the transmission antenna selection switch and an input side of the first demodulator are connected to each other by a first transmission / reception switch. 1 antenna terminal, and the second fixed terminal of the transmission antenna selection switch and the input side of the second demodulator are switched and connected to the second antenna terminal by a second transmission / reception switch, and the TDD (Time Div
ision Duplexing: time division simultaneous transmission and reception, and n base stations are provided (n is an integer of 2 or more), and the optical interface device has a movable terminal of the first base station of the n base stations. The electric signal is shifted to the first fixed terminal of the n transmission / reception switches connected to the movable terminals of the changeover switch and the first fixed terminal of the n transmission / reception switches, and the intermodulation distortion and the harmonic distortion interfere with each other. N first frequency conversion circuits for converting the signals into frequencies not to be changed, a coupler for combining the output signals of the n first frequency conversion circuits and supplying the signals to the electric / optical converter, A distributor for distributing 2n output signals of the converter, and n distributed outputs from the distributor are supplied, the frequency bands are shifted, and the signals are converted into signals of mutually different frequencies to convert the n transmission / reception signals respectively. N second frequency conversion circuits to be supplied to the second fixed terminal of the changeover switch, and the remaining n distribution output signals of the distributor corresponding to the frequencies of the output signals of the n second frequency conversion circuits And n third frequency conversion circuits respectively connected to the movable terminals of the second changeover switches of the n base stations, the radio base station apparatus comprising: The optical signal is supplied from the electrical / optical converter in the optical interface device, and the optical / electrical converter converts the optical signal into an electrical signal, and outputs n electrical electrical signals of the optical / electrical converter. A first distributor for distributing the signal,
A first frequency conversion circuit for converting each of the n output signals of the first distributor into a signal having the same frequency as the signal frequency corresponding to the signal frequency before conversion of the electrical / optical converter in the optical interface device; Movable terminals are respectively connected to the output sides of the n first frequency conversion circuits, and the n antenna selection switches are interlocked with each other, and a first coupling for combining output signals of the first fixed terminals of these antenna selection switches. A second coupler for combining output signals of second fixed terminals of the n antenna selection switches; first and second antennas for transmitting and receiving radio waves to and from the mobile terminal;
A receiving amplifier, a first transmission / reception switch for switchingly connecting the first antenna to an output side of the first coupler and an input side of the first receiving amplifier, and connecting the second antenna to the second antenna;
A second transmission / reception change-over switch for switching connection between the output side of the coupler and the input side of the second reception amplifier; and second and third distribution switches for n-distributing the respective output signals of the first and second reception amplifiers.
A splitter, and n second frequency converters for converting the n-divided output signals of the second splitter into signals having the same frequency as each of the input signals of the n second frequency converters in the optical interface device. Circuit, and n number of third frequency conversion circuits for converting the n-divided output signals of the third divider into signals having the same frequency as each of the input signals of the n number of third frequency conversion circuits in the optical interface device. A third combiner that combines the output signals of the n second frequency conversion circuits and the output signals of the n third frequency conversion circuits, and converts the output signal of the third combiner into an optical signal And an electrical / optical converter for supplying the optical / electrical converter in the optical interface device, wherein a signal input to the third coupler is subjected to a second signal so that intermodulation distortion and harmonic distortion do not interfere with each other. 2, third frequency A conversion frequency of a switching circuit is set, and each of the antenna selection switches of the n base stations is fixedly connected to a first fixed terminal, respectively, and the first and second transmission / reception switches of the n base stations are respectively provided. And that the n transmission / reception switches of the optical interface device and the first and second transmission / reception switches of the wireless base station device are synchronously switched to enable bidirectional communication. Characteristic mobile communication area expansion device.