JP4095185B2 - Wireless communication base station equipment - Google Patents

Wireless communication base station equipment Download PDF

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Publication number
JP4095185B2
JP4095185B2 JP31626498A JP31626498A JP4095185B2 JP 4095185 B2 JP4095185 B2 JP 4095185B2 JP 31626498 A JP31626498 A JP 31626498A JP 31626498 A JP31626498 A JP 31626498A JP 4095185 B2 JP4095185 B2 JP 4095185B2
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signal
base station
frequency
means
converter
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JP2000152300A (en
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秀一 尾林
一郎 瀬戸
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株式会社東芝
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02DCLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THIR OWN ENERGY USE
    • Y02D70/00Techniques for reducing energy consumption in wireless communication networks
    • Y02D70/40According to the transmission technology
    • Y02D70/46Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication

Abstract

PROBLEM TO BE SOLVED: To save energy required for a different radio communication system in a radio communication base station system where a radio information signal is communicated between a central base station provided with a MODEM section whose function can be changed through software and a simple base station mainly consisting of an antenna port, which are interconnected through an optical fiber. SOLUTION: In the radio communication base station system where a plurality of simple base stations 1 each mainly consisting of an antenna port and a central base station 2 that modulates/demodulates radio signals sent/received through antennas of a plurality of the simple base stations and controls channels of them are provided and a radio information signal is communicated through optical fibers between the simple base stations and the central base station, the central base station is provided with a MODEM section 13 employing digital signal processing whose function can be controlled through software and with a control section 14 that varies a frequency conversion amount of the simple base stations and an operating bandwidth of an A/D converter 10 and a D/A converter 18.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radio communication base station apparatus including a centralized base station and a simple base station connected by optical fibers, a radio signal optical transmission receiver and a radio signal optical transmission transceiver used in the radio communication base station apparatus About.
[0002]
[Prior art]
With the rapid increase in demand for wireless communications including mobile communications, it is required to provide wireless communications services even in closed spaces where it is difficult for radio waves to reach, such as inside buildings, behind buildings, inside tunnels, and underground shopping streets. .
[0003]
Since such an area has many obstacles that block radio waves, it is necessary to cover it with a large number of small cells, and accordingly, a large number of radio communication base stations are required. Therefore, the configuration of the radio communication base station applied to the cell is required to be simple, small and low in power consumption.
[0004]
What can be considered as a wireless communication base station for a cell that can be used in light of such a request includes a wireless repeater and a leakage cable, but these currently used are to prevent malfunctions due to oscillation, There are problems such as complicated apparatus configuration, narrow transmission band and inability to handle high frequency signals.
[0005]
Therefore, a simple base station mainly composed of antenna ports is installed in each cell. A separate concentrated base station that performs modulation / demodulation and line control of radio signals transmitted / received by these multiple simplified base stations is provided separately, and the simplified base station of each cell is connected to the concentrated base station via an optical fiber. A wireless base station system for a closed space area service using a simple base station group integrated management operation method in which a wireless information signal is transmitted is drawing attention. This wireless communication base station has advantages such as the ability to route transmission lines without worrying about interference from other radio waves due to the low interference characteristics of optical fibers, and the ability to transmit large-capacity wireless information signals due to the broadband characteristics of optical fibers. .
[0006]
Such a wireless communication base station system for closed space area service transmits WLL (wireless local loop) or a narrowband signal having a low transmission rate to the uplink at a low frequency and a broadband having a high transmission rate to the downlink. Application to a communication system service using different wireless interfaces, such as transmitting a signal at a high frequency, is also considered.
[0007]
By the way, the concentrated base station used in the wireless communication base station system for closed space area service requires a number of modems corresponding to a large number of terminals connected to each simple base station. Tend to be larger.
[0008]
Therefore, it is required to further reduce the size of the modem unit by configuring the modem unit not with an analog signal processing system but with a digital signal processing system such as a digital signal processor (DSP). In particular, a wireless device using a DSP (hereinafter referred to as a software wireless device) that can change a modulation / demodulation function by software is expected because a change to a new wireless communication service can be performed without replacing hardware.
[0009]
FIG. 34 shows an example of this radio communication base station apparatus. In the configuration shown in FIG. 34, 1 is a simple base station, 2 is a concentrated base station, 3 is an optical fiber as a transmission line connecting both base stations 1 and 2, 4 is an antenna of the simple base station 1, 5 is a circulator, 6 Is an amplifier, 10 is an analog-digital converter (A / D), 11 is an electro-optical converter, 12 is an optical-electric converter, 13 is a modem, 18 is a digital-analog converter (D / A), 114 is A digital signal processor (DSP) 115 is a software control unit, and a radio signal received from the antenna 4 as an upstream signal from the simple base station 1 to the centralized base station 2 is converted into an electric-optical converter in the simple base station 1. After being converted into an optical signal by (E / O) 11, it is transmitted toward the centralized base station 2 over the optical fiber 3.
[0010]
In the central base station 2, the transmitted optical signal is received by its own optical-electrical converter (O / E) 12 and converted into an electrical signal to obtain a radio signal. Then, the signal is input to the modem 13 to which software radio equipment technology is applied and demodulated.
[0011]
Downlink signals from the centralized base station 2 to the simplified base station 1 are modulated by the modulator / demodulator 13 in the centralized base station 2, and then light is transmitted by the electro-optical converter (E / O) 11 in the centralized base station 2. After being converted into a signal, it is transmitted to the simplified base station 1 via the optical fiber 3. The simplified base station 1 receives the transmitted optical signal by an optical-electrical converter (O / E) 12 and converts it into an electrical signal, which is amplified by an amplifier 20 to obtain a radio signal. This is transmitted as radio waves from the antenna 4 into the air.
[0012]
In the simple base station 1, when the operating frequency band of the components of the electric-optical converter and the optical-electrical converter is lower than the frequency band of the radio signal, the frequency conversion means is provided to convert the frequency of the RF band. To do.
[0013]
By the way, the use frequency band of wireless communication represented by mobile communication is, for example, 900 [MHz] band and 1.5 [GHz] band for cellular phones, and 1.9 [GHz] for PHS (Personal Handyphone System). ] A band is used. However, since demands are steadily increasing, these alone will not be able to cover demands in the near future. Therefore, new frequency bands such as 2 [GHz] band, 5 [GHz] band, 20 [ Use of the [GHz] band, 40 [GHz] band, and 60 [GHz] band and expansion of the bandwidth of wireless signals are considered.
[0014]
In providing a new wireless communication service, in the wireless communication base station system for closed space area service, wireless information signals having various frequency bands, signal bands, and modulation / demodulation methods as described above are transmitted to the antenna of the simple base station. Between the modem and the modem of the centralized base station via an optical fiber.
[0015]
In order to provide a new wireless communication service, it is necessary to replace or add hardware such as an electric-to-optical converter in a simple base station. This means that simple base stations are distributed and many are arranged. Considering the situation, the working time and cost are enormous, making it difficult to implement in reality.
[0016]
Therefore, it is necessary to eliminate such work. For this purpose, high-speed optical-electrical converters, electrical-optical converters, etc. that can transmit and receive not only narrowband wireless signals or signals with low carrier frequency but also wideband wireless signals or signals with high carrier frequency to simple base stations in advance. It is conceivable to prepare these components in advance.
[0017]
However, for a narrowband radio signal or a signal with a low carrier frequency, the analog processing electric circuit in the converter is faster than necessary, and consumes a large amount of power. Furthermore, the analog processing unit in the simple base station must be high-speed according to the frequency band of the radio signal, and due to the weak noise resistance of the analog signal, components with strict specifications such as low-noise and high-amplification amplifiers are required. Desired.
[0018]
Usually, such components consume a lot of power. Also, with regard to the optical transmission characteristics between a simple base station and a centralized base station, analog transmission has severe restrictions on the linear characteristics and transmission distance of the laser in the electrical / optical converter, and it is necessary to add a protection circuit such as distortion compensation. As a result, more power is consumed.
[0019]
Since a large number of simple base stations are arranged, each individual power consumption greatly affects the overall power consumption for the wireless communication base station system for the closed space area service, which causes the base station operation cost to increase. Moreover, since the heat sink and the power supply capacity for backup are increased according to the power consumption, it is necessary to increase the arrangement space. Therefore, the scale of a simple base station becomes large and it becomes difficult to install it in a narrow closed space or a utility pole.
[0020]
Further, when the power consumption is large, heat is likely to be accumulated in the components, and the durability of each component is also lowered, so that the reliability and stability with respect to the simple base station are also lowered. Therefore, the simple base station is required to have low power consumption, and a method including a high-speed component that can handle various wireless signals as described above is not suitable.
[0021]
[Problems to be solved by the invention]
As described above, as a method for improving the communication service in the closed space area, the closed space area is made into a cell, a simple base station is provided in each cell, and a centralized base station is provided to manage these in an integrated manner. In a wireless communication base station system for closed space area service (system configured with simple base stations and centralized base stations) that is connected by optical fiber and manages and operates simple base stations, different frequency bands that are different wireless communication services, In order to support radio signals with a signal bandwidth, it is conceivable to provide components such as a sufficiently high speed optical / electrical converter and electrical / optical converter on the simple base station side.
[0022]
However, for a radio signal having a low frequency band and a narrow bandwidth, a simple base station requires a larger power consumption than necessary.
[0023]
For this reason, the power consumption of the entire wireless communication base station system for closed space area service including a large number of simple base stations cannot be suppressed, and the operation cost of the base station increases. Further, since the heat sink and the power supply capacity for backup increase in accordance with the power consumption, an increase in installation space is inevitable. That is, the scale of the simple base station becomes large, and it becomes difficult to install the simple base station in a narrow closed space or a utility pole.
[0024]
Further, if the power consumption is large, heat is likely to be accumulated in the components, and therefore, the durability of each component is also lowered, so that the reliability and stability with respect to the simple base station are also lowered.
[0025]
From the above viewpoint, the simple base station is required to have low power consumption, and the method of providing a high-speed component that can handle radio signals in various frequency bands as described above is not suitable. .
[0026]
Accordingly, an object of the present invention is to make a closed space area into a cell as a method for improving communication service in the closed space area, and to provide a simple base station in each cell and to manage them comprehensively. In a closed space area service wireless communication base station system (a system having a configuration of a simple base station and a centralized base station) in which a centralized base station is established and connected by optical fiber, and a simple base station group is managed and operated, An object of the present invention is to provide a wireless communication system that is low in power consumption and small in size, and that can easily cope with the expansion of the used radio frequency band.
[0027]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as follows.
[0028]
[1] A radio communication base station apparatus according to the first invention includes a plurality of base stations that perform radio communication with terminals in a radio zone, and a central base station that performs centralized control on these base stations. And a means for transmitting a wireless information signal related to a wireless communication signal transmitted / received by the base station via an optical fiber connecting the base station and the centralized base station. In a radio communication base station apparatus equipped with modulation / demodulation means that is capable of changing the band and changing the modulation / demodulation function by software.
The base station includes
First frequency conversion means for converting the frequency of a wireless communication signal to be transmitted;
Second frequency converting means for converting the frequency of the received wireless communication signal;
A conversion band variable analog-digital conversion means for converting the radio communication signal frequency-converted by the second frequency conversion means into a digital signal for transmission to the centralized base station;
A conversion band variable digital-analog conversion means for converting a wireless information signal modulated and transmitted from the centralized base station into an analog signal and supplying the analog signal to the first frequency conversion means;
Generates a frequency conversion amount of the first and second frequency conversion means and a signal for controlling a conversion band of the analog-digital conversion means and the digital-analog conversion means from a variable control signal sent from the central base station And means for
The central base station includes
Control means for generating, as a control signal, a frequency conversion amount of the frequency conversion means on the base station side and a signal for variably controlling the conversion band of the analog-digital conversion means and the digital-analog conversion means;
A means for adding the control signal generated by the control means to the wireless information signal is provided.
In the present invention, the A / D converter and the D / A converter are provided in the simplified base station side instead of the software defined radio on the centralized base station side, and the analog signal processing unit in the wireless communication base station is reduced. The specifications of the components in the simple base station or the conditions for optical transmission between the base stations can be relaxed, and low power consumption of the simple base station can be achieved. In addition, a sufficiently high speed A / D converter and D / A converter consumes a large amount of power for a wireless signal with a narrow bandwidth, so a frequency conversion unit is provided in a simple base station, By converting a signal with a high carrier frequency into a low signal and using an operating frequency band equal to that with a signal with a low carrier frequency, the A / D converter, D / A converter, or the electrical circuit in each converter can be slowed down. Power consumption can be suppressed. Furthermore, the amount of frequency conversion in the frequency converter is controlled so that wireless signals having various frequency bands are included in the operating frequency band of each component such as an A / D converter. The A / D converter and the D / A converter operating bandwidth are controlled to provide a simple base station with low power consumption.
The frequency conversion amount, the A / D converter, and the operation bandwidth of the D / A converter are controlled from the central base station, thereby adding a control function for a new wireless communication service. In addition, it is possible to reduce working time and cost without having to replace or add hardware of each simple base station.
[0029]
[2] The radio communication base station apparatus according to the second aspect of the present invention is the radio communication base station apparatus according to the first aspect of the present invention, wherein the base station includes a first base station used for frequency conversion of the radio communication signal. A variable frequency oscillator, a second variable frequency oscillator used for the clock frequency of the A / D converter and the D / A converter, and means for varying the oscillation frequency of the first and second variable frequency oscillators; Means for varying the A / D converter and the conversion band of the D / A converter according to the clock frequency, the centralized base station includes the A / D converter on the base station side and the conversion of the D / A converter Means for determining the frequency conversion value of the band and the wireless communication signal, and transmitting the output of the determining means to the oscillation frequency variable means of the variable frequency oscillator of the base station, A / D converter and conversion band of the D / A converter Characterized in that it comprises means for controlling.
[0030]
When digitally transmitting a wireless information signal from a simple base station to a centralized base station, first, the analog wireless information signal is converted into a digital signal by an A / D converter. At that time, in order to include wireless signals having various frequency bands and signal bands within the band of the A / D converter, it is necessary to change the local frequency used in the frequency down-conversion, Therefore, it is necessary to change the sampling rate of the A / D converter. Therefore, by controlling the clock frequency related to the sampling frequency of the variable frequency oscillator and the A / D converter that oscillates the local frequency from the central base station, when a control function for a new wireless communication service is added, etc. However, it is not necessary to replace or add hardware of each simple base station, and the working time and cost can be reduced. Similarly, the clock frequency of the D / A converter and the local frequency for frequency up-conversion may be controlled in the wireless information signal from the concentrated base station to the simple base station that is a downlink signal.
[0031]
[3] A radio communication base station apparatus according to the third invention includes a plurality of base stations that perform radio communication with terminals in a radio zone, and a central base station that performs centralized control on these base stations. And a means for transmitting a wireless information signal related to a wireless communication signal transmitted / received by the base station via an optical fiber connecting the base station and the centralized base station. In a radio communication base station apparatus comprising modulation / demodulation means for performing digital signal processing
The centralized base station is
Means for transmitting a radio information digital signal, a clock frequency signal Sc, and a frequency conversion signal Sm (however, a frequency component of Sc ≦ a frequency component of Sm) to the base station;
The base station includes
Means for obtaining a radio information digital signal, a clock frequency signal Sc and a frequency conversion signal Sm from the signal transmitted from the central base station;
First frequency conversion means for up-converting a wireless communication signal to be transmitted using the frequency conversion signal Sm;
A second frequency conversion means for down-converting the received wireless communication signal using the frequency conversion signal Sm;
An analog-to-digital conversion means with variable conversion band for operating the radio communication signal frequency-converted by the second frequency conversion means to be converted into a digital signal by operating in correspondence with the clock frequency signal Sc for transmission to the centralized base station. When,
A digital information / analog conversion means having a variable conversion band for converting the radio information signal modulated from the centralized base station into an analog signal by operating in correspondence with the clock frequency signal Sc and supplying the analog signal to the first frequency conversion means. The A / D converter and the band of the D / A converter are varied using the clock frequency signal Sc, and the frequency conversion of the antenna transmission / reception signal is performed using the frequency conversion signal Sm. It is characterized by performing.
[0032]
As described above, in order to transmit radio signals having various frequency bands and signal bands, it is necessary to change the clock frequency of the A / D converter and the D / A converter and the oscillation frequency for frequency conversion. is there.
These are output from a variable frequency oscillator with variable frequency, but the frequency variable range is finite. For this reason, it is conceivable that the frequency band of the region that can accommodate new types of terminals is outside the variable range. At that time, it is difficult to change the equipment for each of the simple base stations arranged in large numbers. Therefore, those frequency transmitters are arranged on the concentrated base station side and distributed to each simple base station. By doing so, even if it is necessary to change the variable frequency oscillator, it is only necessary to replace it on the centralized base station side, and the work can be greatly simplified compared to the work to be changed for each simple base station. .
[0033]
[4] The radio communication base station apparatus according to the fourth invention is the radio communication base station apparatus according to the first invention, wherein the centralized base station transmits a radio information digital signal to the simplified base station. Means for changing the A / D converter and the conversion band of the D / A converter according to the clock frequency, and means for reproducing the clock frequency fc from the transmitted radio information digital signal. The reproduced clock frequency fc is used as the clock frequency of the A / D converter and the D / A converter. When transmitting the clock frequency of the A / D converter and the D / A converter from the concentrated base station side, the configuration becomes complicated, for example, a filter for separating the frequency is required on the simple base station side. The clock frequency of the A / D converter and the D / A converter is usually the modulation frequency of the digital signal or its multiplied frequency. Further, when receiving the optical signal, the simple base station side regenerates the clock signal from the transmitted digital signal. By using the clock frequency as a clock signal for the A / D converter and the D / A converter, the configuration on the simple base station side is simplified.
[0034]
[5] The radio communication base station apparatus according to the fifth invention is the radio communication base station apparatus according to the fourth invention, wherein the centralized base station receives the radio information digital signal and the frequency conversion signal Sm. Means for transmitting to the simple base station, the simple base station using the means for extracting the frequency conversion signal Sm from the signal transmitted from the centralized base station and the frequency conversion signal Sm, It is characterized by performing frequency conversion of a wireless communication signal.
[0035]
Multiplexing of the digital signal and the analog frequency signal Sm can be performed by an adder, and even in a simple base station, the digital signal and the analog frequency signal Sm can be easily separated and extracted by a filter. Therefore, the frequency conversion signal Sm can be transmitted between the concentrated base station and the simplified base station without complicating the configuration in the base station. The radio communication base station apparatus according to the sixth aspect of the present invention is the radio communication base station apparatus according to any one of the third, fourth and fifth aspects, wherein the radio information digital signal transmitted from the central base station to the simple base station It is characterized by adding a band limitation for blocking waves.
[0036]
In general, since harmonics generated from a digital signal are spread over a wide range, there is a possibility of covering the band of the superimposed clock frequency signal or oscillation frequency signal. Such a harmonic becomes a noise source of the clock frequency and the oscillation frequency, and becomes a noise of a radio signal or leads to a malfunction of the A / D and D / A converter.
[0037]
Therefore, before superimposing the clock frequency signal or the like on the digital signal, the low-frequency transmission filter is transmitted to block the harmonics. With such a configuration, the above-described harmonic overburden is suppressed, and stable transmission of a clock signal or an oscillation frequency signal is provided.
[0038]
[7] A radio communication base station apparatus according to the seventh invention includes a base station that performs radio communication with a terminal in a radio zone, and includes a central base station that performs centralized control for each of the plurality of base stations. Provided with means for transmitting a radio information signal related to a radio communication signal transmitted / received by the base station via an optical fiber between the base station and the central base station, the central base station including the radio communication signal In a radio communication base station apparatus, the modulation / demodulation function of the modulation / demodulation unit is performed by digital signal processing, and the modulation / demodulation function can be changed by software. A digital-analog (D / A) converter that converts the output digital signal into a first wireless information analog signal, and a frequency signal for frequency conversion of the first wireless information analog signal and the wireless communication signal means for transmitting m to the simple base station, means for receiving the second radio information analog signal transmitted from the simple base station, and input of the second radio information analog signal to the modulator / demodulator. An analog-to-digital (A / D) converter for converting into a digital signal, and the simplified base station includes means for obtaining the first radio information analog signal and the frequency signal Sm transmitted from the centralized base station; Means for converting the frequency of the first radio information signal using the frequency signal Sm and obtaining a radio communication signal to be transmitted to the terminal; receiving the radio communication signal from the terminal; and using the frequency signal Sm Means is provided for obtaining the second radio information analog signal by frequency conversion, and means for transmitting the second radio information analog signal to the concentrated base station side.
[0039]
According to the present invention, on the simple base station side, the first radio information analog signal and the radio reception signal are frequency-converted into radio signals of various frequency bands. It is possible to reduce the power consumption of a simple base station without giving an extra band to the optical converter.
[0040]
By controlling the frequency for frequency conversion from the centralized base station, even when adding a frequency band for a new wireless communication service, the centralized base station does not need to be replaced or added. Since only the hardware on the base station side needs to be changed, work time and cost can be reduced.
[0046]
As described above, the present invention has expandability and flexibility that can correspond to wireless communication systems having different frequency bands or bands of different types of wireless communication services, and a narrowband wireless signal or a signal having a low carrier frequency and a broadband wireless signal or carrier frequency. An object of the present invention is to provide a wireless signal light transmission receiver and a wireless signal light transmission transmitter / receiver or a wireless communication base station apparatus capable of suppressing power consumption even when transmitting and receiving a high signal.
[0047]
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a wireless communication base station system for closed space area service (a system having a configuration of a simple base station and a centralized base station) that can support radio signals of various frequency bands and signal bandwidths, An embodiment of the present invention will be described below with reference to the drawings.
[0048]
(First embodiment)
FIG. 1 is a block diagram showing a first embodiment of the first and second inventions. In the figure, 1 is a simple base station that performs radio communication with terminals in a radio zone, 2 is a concentrated base station, and the simple base station 1 divides the closed space into small cell areas, and each cell area A simple base station 1 is installed for each service area. A plurality of such simple base stations 1 are taken as a group, and a centralized base station 2 that performs centralized control for the simple base station group is provided. The simple base station 1 and the centralized base station 2 are connected by an optical fiber 3, and wireless information Signals are converted into optical signals for transmission.
[0049]
The configuration will be described in detail. The simple base station 1 includes an antenna 4, a circulator 5, a low noise amplifier 6, a local oscillator 7, mixers 8t and 8r, a low-pass filter 9, an analog-digital converter (A / D) 10, an electro-optic A converter (E / O) 11 s, an optical-electric converter (O / E) 12 s, a simple base station controller 16, a D / A converter 18, a high-pass filter 19, and a power amplifier 20 are configured. .
[0050]
Among these, the antenna 4 is for transmitting and receiving radio waves, the circulator 5 sends a transmission signal from the transmission system to the antenna 4, and sends a reception signal from the antenna 4 to the reception system. This is a path switcher with directionality for path switching.
[0051]
The optical-electrical converter (O / E) 12s is for converting an optical signal sent from the centralized base station 2 side via the optical fiber 3 into an electrical signal. The electrical-optical converter (E / O) 11s is for converting the digital data output from the A / D converter 10 into an optical signal and sending it out to the optical fiber 3.
[0052]
The D / A converter 18 converts an electrical signal output from the optical-electrical converter (O / E) 12 s into an analog signal, and can be controlled by the simple base station controller 16. It has become. The A / D converter 10 converts the output of the low-pass filter 9 into a digital signal and outputs it to an electro-optical converter (E / O) 11s. The simple base station controller 16 performs sampling frequency. Can be controlled.
[0053]
The local oscillator 7 is an oscillation frequency variable type oscillator that oscillates a signal of a required frequency, and has a configuration in which the oscillation frequency is controlled by the simple base station controller 16. The mixer 8t multiplies the signal oscillated by the local oscillator 7 and the output signal of the D / A converter 18, and performs frequency up-conversion. The high-pass filter 19 converts the noise in the frequency up-converted signal. This is a filter for removing an image to be removed. The power amplifier 20 is an amplifier that amplifies the output from the high-pass filter 19 for wireless transmission and sends it to the circulator 5.
[0054]
The amplifier 6 amplifies the signal received by the antenna 4 input via the circulator 5, and the mixer 8 r multiplies the signal output from the amplifier 6 with the local oscillation signal from the local oscillator 7. The frequency is down-converted. The low-pass filter 9 is a filter for image removal given to the A / D converter 10 that extracts a low-frequency component of the signal frequency-converted by the mixer 8r.
[0055]
The simple base station controller 16 is responsible for various controls of the simple base station 2, and controls the oscillation frequency of the local oscillator 7 according to a control command from the centralized base station 2 side, and also the D / A converter 18. In addition, the sampling rate of the A / D converter 10 can be freely changed and controlled.
[0056]
Further, as shown in FIG. 1, the centralized base station 2 includes an electrical / optical converter (E / O) 11m, an optical / electrical converter (O / E) 12m, a modulator / demodulator 13, a centralized base station controller 14, And an adder 15.
[0057]
Here, the electrical-optical converter (E / O) 11m is for converting an electrical signal into an optical signal and sending it to the optical fiber 3, and the optical-electrical converter (O / E) 12m is An adder 15 is used to convert an optical signal transmitted through the optical fiber 3 into an electrical signal. The adder 15 controls the signal from the modem 13 and the control for the simplified base station 1 from the centralized base station controller 14. The addition output is provided to an electro-optical converter (E / O) 11m.
[0058]
Further, the modem 13 modulates the information signal 53 transmitted from the communication partner into a digital radio information signal and outputs it to the adder 15, and also an optical-electric converter (O / E) 12m. The demodulated signal 52 obtained by demodulating the electric signal converted and output in step 1 is output.
[0059]
The modulator / demodulator 13 is a modulator / demodulator whose function can be changed by software, and includes a software control unit 115 and a digital signal processing unit (DSP) 114, and the modulation / demodulation of the digital signal processing unit 114 by the software control unit 115. Function can be changed.
[0060]
The centralized base station controller 14 has a function of generating a control signal for the simple base station 1 and supplying it to the adder 15 or controlling various controls of the modem 13.
[0061]
In this system having such a configuration, in the simple base station 1, a high-frequency radio signal received by the antenna 4 is guided to the receiving system by the circulator 5, amplified by the low-noise amplifier 6 of the receiving system, and then the local oscillator 7 is multiplied by the local oscillation signal from the mixer 8r and frequency down-converted.
[0062]
Then, it passes through the low-pass filter 9 for image removal and is converted into a digital signal by the analog-digital converter 10. The converted digital signal is converted into an optical signal 51 by the electro-optical converter 11 and transmitted to the centralized base station 2 through the optical fiber 3.
[0063]
In the centralized base station 2, the transmitted digital optical signal 51 is converted into an electrical signal by an optical-electrical converter (O / E) 12. Then, the electrical signal is demodulated by the modulator / demodulator 13 including a digital signal processing (DSP) 114 whose modulation / demodulation function can be changed by the software control unit 115 to become a demodulated signal 52 and transmitted to the communication partner. Also, the information signal 53 transmitted from the communication partner is modulated by the modem 13 into a digital radio information signal.
[0064]
Then, the control signal for the simplified base station 1 from the centralized base station controller 14 is superimposed by the adder 15, converted into the optical signal 54 in the electro-optic converter 11, and simplified through the optical fiber 3. It is transmitted to the base station 1 side.
[0065]
In the simplified base station 1, the transmitted wireless information optical signal 54 is converted into an electrical signal by the optical-electrical converter (O / E) 12 and branched into two, one of which is sent to the simplified base station controller 16. The other, after demodulating the wireless information signal, is converted into an analog signal by the D / A converter 18 and becomes an analog wireless information signal. This analog wireless information signal is multiplied by the local oscillation signal from the local oscillator 7 in the mixer 8t, frequency up-converted, and from the antenna 4 via the high-pass filter 19 for image removal, the power amplifier 20, and the circulator 5, to the mobile terminal. Sent to.
[0066]
At this time, the simple base station controller 16 appropriately adjusts the sampling frequency of the D / A converter 17 and the A / D converter 10 according to the frequency and bandwidth of the transmission / reception signal according to the control signal from the centralized base station 2. In addition, the oscillation frequency of the frequency converting oscillator 7 is controlled to be an appropriate value in accordance with the frequency and bandwidth of the transmission / reception signal.
[0067]
<Modulator / demodulator whose function can be changed>
The modulator / demodulator 13 in the present system is configured such that the function can be changed by software based on the configuration based on the software control unit 115 and the digital signal processing (DSP) 114, but as a modulator / demodulator capable of changing the function by software, Although the configuration is different, there is a technique that has been conventionally used.
[0068]
In order to clarify the configuration and effects of this system, the difference between the conventional radio technology using a modem that can change the function by software and the modem 13 in this system and the improvements are compared. This will be described in detail.
[0069]
First, the conventional technology will be mentioned. A conventional modulator / demodulator of this type (software modulator / demodulator) includes an A / D converter and a D / A converter. As shown in FIG. 2, a radio apparatus configured using the conventional software modulator / demodulator. It becomes. That is, as shown in FIG. 2, a high-frequency analog unit 2101, an analog / digital (A / D) converter 2102, a digital / analog (D / A) converter 2103, an FPGA 2104 for down-conversion processing loaded with digital down-conversion software, Digital signal processing IC (hereinafter also referred to as DSP (Digital Signal Processor)) 2105 loaded with modem software, channel codec software, voice codec software, etc., which supports multi-access methods, control software for wireless transmission / reception Control MPU (hereinafter, also referred to as MPU) 2106, which is a processor for loading A, D, A / D converter 2102, D / A converter 2103, FPGA 2104, DSP 2105, and control MPU 2106 It is composed of a respective clock source 2107,2108,2109,2110,2111 for generating a clock signal required for.
[0070]
The A / D converter 2102, the D / A converter 2103, the FPGA 2104, the DSP 2105, and the MPU 2106 constitute a modem unit.
[0071]
A major feature of this software defined radio is that it processes post-modulation at the digital data level. By changing the software of the FPGA 2104, DSP 2105, and MPU 2106 necessary for this processing, different wireless systems can be used without changing hardware. It is possible to cope with modulation / demodulation.
[0072]
In the wireless system, the radio wave to be transmitted / received is an analog signal. Therefore, even in the digital processing system, after all, it cannot be transmitted wirelessly unless it is converted into an analog signal. A / D converter 2102 and a D / A converter 2103 are provided.
[0073]
When configuring the radio so that the frequency band and signal bandwidth of all radio signals are included in the operating frequency band, the A / D converter 2102 and the D / A converter 2103 also operate with the maximum required specifications. Therefore, it is necessary to be able to handle the signal of the maximum frequency band that may be used, so that it is driven with the necessary high-speed sampling operation in the maximum frequency band. It will be.
[0074]
Since the power consumption inevitably increases when the device is operated at a high speed, the A / D converter 10 and the D / A converter 18 that are operated at a high speed have a low frequency band. Or it is faster than necessary when processing a radio signal with a narrow signal bandwidth, and this is over-spec.
[0075]
Therefore, when processing a radio signal with a low frequency band or a narrow signal bandwidth, power consumption is unnecessarily large.
[0076]
In this system, in order to save such power consumption and save energy, the radio signal is down-converted into a specific frequency band, and the A / D converter 10 and the D / A converter 18 Even if the operating frequency band is lowered, no problem occurs, the operating frequency is lowered, and the power consumption of these A / D converter 10 and D / A converter 18 is reduced.
[0077]
That is, in order to reduce power consumption, first, radio signals in various frequency bands are down-converted into a specific range of frequency bands, and the operating frequencies of the A / D converter 10 and the D / A converter 18 are reduced. The band is made low and power consumption is reduced.
[0078]
Therefore, it is necessary to change the oscillation frequency of the local oscillator 7. In this system, the frequency value of the local oscillator 7 is controlled from the concentrated base station 2 side via the simple base station controller 16. For radio signals having different signal bandwidths, the power consumption is reduced by combining the bands of the A / D converter 10 and the D / A converter 18.
[0079]
That is, some A / D converters and D / A converters have a configuration in which the band can be changed according to the reference clock frequency. Such a band variable type is used as the A / D converter 10 and the D / A converter 18, and these are provided on the simple base station 1 side so that the simple base station can receive the command from the centralized base station 1. The clock frequency may be changed via the two simple base station controllers 16 and control may be performed to change the bands of the A / D converter 10 and the D / A converter 18.
[0080]
In addition, the central base station and the simplified base station are connected with an optical fiber to transmit information optically. Generally, the photoelectric conversion element used for optical transmission has a lower band than the frequency band of the radio signal. Frequency down-conversion and frequency up-conversion are performed on the simple base station 1 side lower than the frequency band. Then, frequency conversion is performed on the simple base station 1 side, and the operating frequency bands of the electro-optical converters 11s and 11m and the optical-electric converters 12s and 12m are lowered, so that these conversion devices (electric-optical converter 11s 11m and the photoelectric converters 12s, 12m) can be reduced. In other words, if frequency conversion is to be performed, frequency conversion is performed on the simple base station 1 side, and the operating frequency band of the electro-optical converters 11s, 11m and the optical-electric converters 12s, 12m is lowered to reduce power consumption. It is good to reduce.
[0081]
The wireless communication base station apparatus related to the first includes a base station that performs wireless communication with a terminal in a wireless zone, and includes a centralized base station that performs centralized control for each of the plurality of base stations, A radio information signal related to a radio communication signal transmitted / received at a base station is transmitted between the base station and the centralized base station via an optical fiber, and a modem unit for the radio information signal is provided in the centralized base station. A modulation / demodulation function of the modulator / demodulator unit is performed by digital signal processing, and a radio communication base station apparatus capable of changing the modulation / demodulation function by software,
The base station includes means for converting the frequency of the wireless communication signal, an analog-digital (A / D) converter for converting an analog signal corresponding to the wireless communication signal into a digital signal, and converting the digital signal into a wireless communication signal. A digital-to-analog (D / A) converter that converts the signal into a corresponding analog signal, and the central base station includes a frequency conversion amount of the frequency conversion means on the base station side, the A / D converter, and the D And a means for controlling and varying the conversion band of the / A converter.
[0082]
In this embodiment, an A / D converter and a D / A converter are provided in the simplified base station side, not in the software radio on the centralized base station side, so that the analog signal processing unit in the radio communication base station is reduced. As a result, the specifications of the components in the simple base station or the conditions of optical transmission between the base stations can be relaxed, and low power consumption of the simple base station can be achieved. In addition, sufficiently fast A / D converters and D / A converters have excessive performance when the processing target is a wireless signal with a narrow bandwidth, and consume large amounts of power unnecessarily. In order to avoid unnecessary cost increase due to the use of elements of over-performance and over-performance, in the system of this embodiment, a simple base station is provided with a frequency conversion unit to convert a signal with a high carrier frequency into a low signal, The operating frequency band equal to the low frequency signal was specified. As a result, the A / D converter, the D / A converter, or the electric circuit in each converter can be slowed down, the cost can be reduced, and the power consumption can be suppressed.
[0083]
Furthermore, in order to include wireless signals having various frequency bands in the operating frequency band of each component such as an A / D converter, the frequency conversion amount in the frequency conversion unit can be controlled, and various signals can be controlled. A simple base station that can handle various frequency bands with low power consumption by controlling the operating bandwidth of the A / D converter and D / A converter for the band. Can be provided.
The frequency conversion amount, the A / D converter, and the operation bandwidth of the D / A converter are controlled from the central base station, thereby adding a control function for a new wireless communication service. In addition, it is possible to reduce the working time and cost without replacing or adding hardware of each simple base station.
[0084]
(Second embodiment)
FIG. 3 is a block diagram showing the second embodiment, which corresponds to the third invention of the present application. In FIG. 3, the main configurations of the simple base station 1 and the centralized base station 2 are the same as those of the first embodiment. However, the local oscillator 7 in the configuration of the simple base station 1 in the first embodiment is abolished, and a high-pass filter (HPF) 22 and a band-pass filter (BPF) 24 are provided instead, and an optical-electric conversion unit (O / E) ) The high-frequency component of the transmission signal from the centralized base station 1 converted into the electric signal in 12 is extracted by the high-pass filter (HPF) 22 and given by the adder 8r, and the photoelectric conversion unit (O / E) ) The band component of the transmission signal from the centralized base station 1 converted into the electrical signal in 12 is extracted by the band pass filter (BPF) 24 and supplied to the D / A converter 18.
[0085]
In the central base station 2, oscillators 21a and 21b whose oscillation frequency can be controlled by the controller 14 are added, a frequency signal having a desired frequency is oscillated by the oscillator 21a, and a clock signal having a desired frequency is oscillated by the oscillator 21b. In addition to the configuration, the outputs of the oscillators 21 a and 21 b are added to the modulation signal output from the modulator / demodulator 13 by the adder 15 and supplied to the electro-optical converter 11.
[0086]
In order to suppress the power consumption of the simple base station 1, it is necessary to change the frequency of the local oscillator 7, the reference clock frequency of the D / A converter 18 and the A / D converter 10 as described in the first embodiment. There is. In this case, it is a proposal to provide a frequency variable local oscillator in advance on the simple base station 1 side, but since the frequency variable range cannot be infinite, in order to cope with a new wireless communication system, It may be necessary to replace or add local transmitters. At that time, replacement or expansion of equipment for all the simple base stations is a difficult task.
[0087]
However, if the frequency source is provided on the concentrated base station 2 side and is distributed to each simplified base station 1, if the device needs to be replaced, the work for that purpose is performed only at the concentrated base station 2. The replacement work at each simple base station is not necessary, and the work cost and the work time are reduced.
[0088]
Further, if active components such as an oscillator including the A / D converter 10 and the clock frequency of the D / A converter 18 are collectively provided on the centralized base station 2 side, consumption in each simple base station Power is reduced.
[0089]
Furthermore, if the frequency signal Sm for frequency conversion and the clock signal Sc of the A / D converter 10 and the D / A converter 18 are transmitted from the centralized base station 2, the configuration on the simple base station 1 side becomes simpler and useful. It is.
[0090]
However, when the frequency signal Sm and the clock signal Sc are multiplexed and transmitted, it is necessary to extract them separately on the simple base station 1 side. Usually, the bands of the A / D converter 10 and the D / A converter 18 are very low with respect to the frequency band of the high-frequency radio signal, and the higher the speed, the more power is consumed. Therefore, when the frequency of the radio signal is down-converted, in order to relax the band conditions of the A / D converter 10 and the D / A converter 18, the frequency conversion is performed to a low band close to DC (direct current). Is good. For this reason, the value of the frequency signal Sm for frequency conversion is often a value close to the frequency of the radio signal, and a relatively high frequency is required.
[0091]
The frequency of the clock signal Sc is “the frequency band of the down-converted signal and how many times the signal is sampled?”, “How many bits the signal amplitude is quantized?”, “A / Although it depends largely on whether the input / output configuration of the D converter 10 is serial-serial or serial-parallel ?, it is usually only tens of times the signal bandwidth.
[0092]
For example, when the carrier frequency is 5 [GHz] and the signal band is 10 [MHz], frequency conversion is performed with Sm = 4.95 [GHz] in order to perform frequency conversion as low as possible. Then, when a signal that spreads over a frequency band of 0 to 10 [MHz] around a frequency of 5 [MHz] is quantized by 8 times sampling and amplitude is 8 [bit], and serial-serial output is obtained, The clock frequency Sc is 10 [MHz] × 8 × 8 = 640 [MHz].
[0093]
In order to easily separate the frequency signal Sm and the clock signal Sc on the simple base station 1 side, it is necessary to multiplex them in different regions in the frequency band. Set so that no frequency band is applied. Since the frequency signal Sm and the clock signal Sc can be used in common, the condition between Sc and Sm is Sc ≦ Sm.
[0094]
The operation of the embodiment will be described in detail.
In the system having the configuration as shown in FIG. 3, in the centralized base station 2, the digital radio information signal 55 output from the modem 13 whose function can be changed by software is sent from the oscillator 21 a whose oscillation frequency is controlled by the controller 14. The frequency signal Sm56 and the clock signal Sc60 from the oscillator 21b whose oscillation frequency is controlled by the controller 14 are superimposed by the adder 15, and then converted into the optical signal 54 by the electro-optical converter 11.
[0095]
FIG. 4 shows the optical spectrum of the optical signal 54.
The digital radio information signal 55 extends from DC to the transmission capacity band, and the local oscillation frequency signal 56 that is analog and the reference clock signal 60 of the A / D converter 10 and the D / A converter 18 are superimposed on the vacant high frequency side. can do. The optical signal 54 is transmitted to the simplified base station 1 side via the optical fiber 3. In the simple base station 1, the transmitted optical signal 54 is converted into an electrical signal by the optical-electrical converter 12, and it is branched. One of the branched signals demodulates the digital radio information signal 55, Input to the digital-analog converter 18.
[0096]
Further, the other branched signal passes through the bandpass filter 24 and the highpass filter 22 to extract the frequency signal 56 having the oscillation frequency Sm and the clock signal 60 having the clock frequency Sc, and the frequency signal 56 can be frequency down-converted or increased in frequency. As a local signal for conversion, the clock signal 60 is used as a reference clock for the A / D converter 10 and the D / A converter 18.
[0097]
In the present embodiment, the oscillators 21a and 21b are configured such that the frequency can be arbitrarily varied by the control unit 14, and by varying the frequency of the oscillation frequency signal 56 and the clock signal 60, an arbitrary band is provided. Transmission and reception of signals in an arbitrary frequency band can be performed by control on the central base station 1 side.
[0098]
As described above, the configuration for controlling the frequency of the local oscillator 7 or the reference clock frequency of the A / D converter 10 and the D / A converter 18 from the centralized base station 2 side is a control function for a new wireless communication service. When a change is made, it is not necessary to make any changes in the simple base stations 1 arranged in large numbers, and only the centralized base station 2 is required, so that a significant reduction in work time and costs can be obtained.
[0099]
However, the operating frequency band of the antenna 4 in the simple base station 1, the band of the filter 19, the band of the mixer 8, the amplifiers 6 and 20, etc. is limited, so that the corresponding range is wide with respect to the frequency band of the radio signal. It is also important to have a design.
[0100]
In addition, in the antenna 4, the filter 19, the mixer 8, and the amplifiers 6 and 20, a plurality of types of components having different operating frequency bands are provided in advance, and a switch or the like is used by a control signal transmitted from the central base station. The component may be variable.
[0101]
In the above-described method of changing the oscillation frequency of the local oscillator 7 and the transmission band of the clock frequency of the D / A and A / D converters 10 and 18, each of the component bases 1 has a plurality of components in advance in the simple base station 1. A means for selecting an input and an output by a switch may be used.
[0102]
(Third embodiment)
Next, an embodiment in which transmission of a clock signal from the centralized base station 2 to the simplified base station 2 is unnecessary and the transmission band can be effectively used correspondingly will be described as a third embodiment.
The third embodiment corresponds to the fourth invention of the present application. In this embodiment, in the A / D converter 10 and the D / A converter 18, the reference clock signal necessary for the operation usually takes a multiplication (1 or more) component of the modulation frequency of the input / output digital signal. Therefore, the regenerated clock signal, which is the modulation frequency of the transmitted digital signal, is used as it is as the reference clock signal in the simple base station 1 or is multiplied if necessary. As a result, simple processing is sufficient, and transmission of a clock signal from the centralized base station 2 to the simple base station 2 can be made unnecessary. Details will be described below.
[0103]
FIG. 5 is a block diagram showing the third embodiment. The main configurations of the simple base station 1 and the centralized base station 2 will be described. The simple base station 1 includes an antenna 4, a circulator 5, a low noise amplifier 6, an analog / digital converter (A / D) 10, an electro-optical converter (E / O) 11 s, an optical-electrical converter (O / E) 12 s, a D / A converter 18, and a power amplifier 20. The optical-electrical converter (O / E) 12s is composed of a photodetector (PD) 26, which is a photoelectric converter, a low-pass filter (LPF) 17, a clock recovery unit 23, and a demodulator (DEM) 27. is there.
[0104]
Among these, the antenna 4 is for transmitting and receiving radio waves, the circulator 5 sends a transmission signal from the transmission system to the antenna 4, and sends a reception signal from the antenna 4 to the reception system. This is a path switcher with directionality for path switching.
[0105]
The optical-electrical converter (O / E) 12s is for converting an optical signal sent from the centralized base station 2 side through the optical fiber 3 into an electrical signal. The optical signal transmitted is converted into an electrical signal by a photodetector (PD) 26, and a low-frequency component is extracted by passing it through a low-pass filter 17, and demodulated into digital data by a demodulator 27 and output. At the same time, a clock signal is regenerated from the low-frequency component obtained by the low-pass filter 17 by the clock regenerating unit 23 and is supplied to the D / A converter 18, the demodulator 27 and the A / D converter 10. Therefore, the A / D converter 10 and the D / A converter 18 are configured to operate with the clock signal regenerated by the clock regenerating unit 23.
[0106]
The electro-optical converter (E / O) 11 s is for converting digital data output from the A / D converter 10 into an optical signal and sending it to the optical fiber 3.
[0107]
The D / A converter 18 converts an electrical signal output from the optical-electrical converter (O / E) 12s into an analog signal, and the output of the optical-electrical converter (O / E) 12s. The data can be converted into an analog signal and output at a frequency corresponding to the clock signal. The amplifier 6 is an amplifier that amplifies the signal received by the antenna 4 input via the circulator 5, and the A / D converter 10 converts the output of the amplifier 6 into a digital signal to convert the signal into an electro-optical converter. (E / O) 11s, which is output to the optical fiber 3 by sampling an analog signal at a frequency corresponding to the clock signal output from the opto-electric converter (O / E) 12s, and converting it to digital data It has a configuration.
[0108]
Further, as shown in FIG. 5, the centralized base station 2 includes an electric-optical converter (E / O) 11 m, an optical-electrical converter (O / E) 12 m, and a modem 13. .
[0109]
Here, the electrical-optical converter (E / O) 11m is for converting an electrical signal into an optical signal and sending it to the optical fiber 3, and the optical-electrical converter (O / E) 12m is An optical signal transmitted from the optical fiber 3 is converted into an electrical signal. The modem 13 modulates an information signal transmitted from a communication partner into a digital radio information signal. The electric signal is output to the electric-optical converter (E / O) 11m, and the electric signal converted and output by the optical-electrical converter (O / E) 12m is demodulated and output.
[0110]
The modulator / demodulator 13 is a modulator / demodulator whose function can be changed by software, and includes a software control unit 115 and a digital signal processing unit (DSP) 114, and the modulation / demodulation of the digital signal processing unit 114 by the software control unit 115. The function can be changed.
[0111]
In this system having such a configuration, the digital base station 2 inputs the digital radio information signal output from the modem 13 to the electro-optical converter 11m and converts it into an optical signal. This optical signal is transmitted to the simplified base station 1 side through the optical fiber 3.
[0112]
In the simple base station 1, the transmitted optical signal is received by the photodetector (PD) 26 in the photoelectric converter 12s, converted into an electrical signal, and branched into two.
[0113]
One of the two branched signals is supplied to the clock recovery unit 23, where the clock signal is recovered from the received signal.
[0114]
The other received signal of the two branches is demodulated by the demodulator 27 after passing through the low-pass filter 17 and input to the D / A converter 18. The D / A converter 18 uses the clock signal regenerated by the clock regenerator 23 and, if necessary, multiplies this clock signal to provide a reference clock signal for the A / D converter 10 and the D / A converter 18. Used as
[0115]
The D / A converter 18 operates in synchronization with the clock signal, converts the digital signal demodulated by the demodulator 27 into an analog signal, and then amplifies the power for radio transmission by the power amplifier 20 before the circulator 5 is operated. To the antenna 4 and transmit.
[0116]
On the other hand, a signal received by the antenna 4 is sent to an amplifier 6 via a circulator 5, amplified there, and then supplied to an A / D converter 10, which is connected to the clock recovery unit. The clock signal regenerated at 23 is operated and sampled as a reference clock, the signal is converted from analog to digital, converted into an optical signal by the electro-optical converter 11s, and then transmitted to the optical fiber 3.
[0117]
In the centralized base station 2, this optical signal is converted into an electric signal by the optical-electrical converter 12m, demodulated by the post-modulator 13, and sent to the connection destination.
[0118]
In this embodiment, the digital signal modulation frequency is extracted from the digital radio signal sent from the centralized base station 2 to the simple base station 1, and the clock is reproduced at this modulation frequency to perform A / D conversion in the simple base station 1. Since it is used as a reference clock signal in the device 10 and the D / A converter 18, it becomes unnecessary to transmit a clock signal from the centralized base station 2 to the simplified base station 2. Since the transmission of the clock signal from the base station 2 to the simple base station 2 is unnecessary, the transmission band can be used effectively.
[0119]
Since the reference clock signals of the A / D converter 10 and the D / A converter 18 usually take a component of multiplication (one time or more) of the modulation frequency of the input / output digital signal, the modulation of the transmitted digital signal is performed. The regenerated clock signal having the frequency can be used as it is, or in a simple process of multiplying if necessary.
[0120]
According to the present invention, since it is not necessary to multiplex and transmit clock signals, the transmission band can be used effectively.
[0121]
(Fourth embodiment)
The fourth embodiment corresponds to the fifth invention of this application. In this embodiment, the clock signal Sc which is the modulation frequency of the digital signal necessary on the central base station 2 side and the frequency signal Sm for frequency conversion are used. Will be described so that the centralized base station 2 can transmit to the simple base station 1 by simple superimposition.
[0122]
FIG. 6 is a block diagram showing the fourth embodiment. The main configurations of the simple base station 1 and the concentrated base station 2 are the same as the configurations of the third embodiment.
[0123]
In this embodiment, in the configuration of the fourth embodiment shown in FIG. 5, the simple base station 1 is further provided with mixers 8t and 8r, high-pass filters 19 and 22, and a low-pass filter 9, and the central base station 2 has Is a configuration in which a centralized base station controller 14, an adder 15, and an oscillator 21 are further provided.
[0124]
Among these, the high-pass filter 22 is a filter for extracting a high-frequency component of the digital electric signal converted by the photo detector (PD) 26 of the photoelectric converter 12s, and the mixer 8t outputs the output of the high-pass filter 22. And the output signal of the D / A converter 18 are multiplied, and the frequency up-conversion is performed. The high-pass filter 19 removes noise in the frequency-up-converted signal and outputs it to the power amplifier 20 for image removal. It is a filter.
[0125]
The mixer 8r multiplies the signal output from the amplifier 6 that amplifies the signal received by the antenna 4 input through the circulator 5 with the output of the high-pass filter 22 to down-convert the frequency.
[0126]
The low-pass filter 9 is an image removal filter that is supplied to the A / D converter 10 that extracts a low-frequency component of the signal frequency-converted by the mixer 8r.
[0127]
The centralized base station controller 14 provided in the centralized base station 2 controls the system of the centralized base station 2, and the frequency oscillator 21 is required under the control of the centralized base station controller 14. The oscillating frequency signal Sm is oscillated by the adder 15 and added to the digital radio information signal modulated and output from the demodulator 13, and then the optical signal is output by the electro-optical converter 11m. It is assumed that the data is converted and transmitted to the simplified base station 1.
[0128]
The operation of this system will be described. In the centralized base station 2, the adder 15 superimposes the oscillation frequency signal Sm from the oscillator 21 controlled by the controller 14 on the digital radio information signal output from the modem 13. Then, it is converted into an optical signal by the electro-optical converter 11m. This optical signal is transmitted to the simplified base station 1 side via the optical fiber 3.
[0129]
In the simplified base station 1, the transmitted optical signal is received by the photo detector (PD) 26 in the photoelectric converter 12s and converted into an electrical signal. This is given to the low-pass filter 17 and the high-pass filter 22.
[0130]
The high-pass filter 22 extracts the oscillation frequency signal Sm by extracting the high frequency component of this signal and uses it as a local signal for frequency down-conversion or frequency up-conversion.
[0131]
The low-pass filter 17 extracts a low-frequency component of the electrical signal converted by the photodetector (PD) 26 and passes it to the demodulator 27 and the clock regenerator 23. The clock recovery unit 23 recovers a clock signal from the signal and supplies it to the demodulator 27, the D / A converter 18, and the A / D converter 10.
[0132]
As a result, the clock reproduction unit 23 reproduces a clock signal having a modulation frequency of the digital signal transmitted from the central base station 2.
[0133]
The demodulator 27 demodulates the output signal of the low-pass filter 17 in synchronization with the clock signal from the clock recovery unit 23, and inputs the demodulated signal to the D / A converter 18. Note that the clock signal regenerated by the clock regenerator 23 is multiplied as necessary when used as a reference clock signal for the A / D converter 10 and the D / A converter 18.
[0134]
The D / A converter 18 operates in synchronization with the clock signal from the clock recovery unit 23, converts the digital signal demodulated by the demodulator 27 into an analog signal, and supplies the analog signal to the mixer 8t. The mixer 8t multiplies the frequency signal Sm extracted from the high-pass filter 22 by the output signal of the D / A converter 18, and performs frequency up-conversion. Then, after removing noise in the frequency up-converted signal by the high-pass filter 19, the power amplifier 20 amplifies the power for wireless transmission, and then sends it to the antenna 4 via the circulator 5 for transmission.
[0135]
On the other hand, the signal received by the antenna 4 is sent to the amplifier 6 via the circulator 5, amplified there, and given to the mixer 8r. The mixer 8r multiplies the signal output from the amplifier 6 with the frequency signal Sm extracted from the high-pass filter 22 to down-convert the frequency. Then, the frequency down-converted signal is sent to the low-pass filter 9, where image removal is performed by extracting the low-frequency component. The low-frequency component extracted by the low-pass filter 9 is given to the A / D converter 10, and the A / D converter 10 operates using the clock signal regenerated by the clock regenerating unit 23 as a reference clock for sampling. On the other hand, the signal is converted from analog to digital, converted into an optical signal by the electro-optical converter 11s, and then transmitted to the optical fiber 3.
[0136]
In the centralized base station 2, this optical signal is converted into an electric signal by the optical-electrical converter 12m, demodulated by the post-modulator 13, and sent to the connection destination.
[0137]
As described above, in this embodiment, the clock signal Sc, which is the modulation frequency of the digital signal required on the concentrated base station 2 side, and the frequency signal Sm for frequency conversion are converted from the concentrated base station 2 to the simplified base station by simple superposition. 1 can be transmitted.
[0138]
(Fifth embodiment)
Next, when transmitting a large-capacity digital wireless information signal from a centralized base station to a simple base station, the oscillation frequency signal Sm and the clock frequency signal Sc can be superimposed without worrying about harmonics. As a fifth embodiment, on the simple base station 1 side, when the oscillation frequency signal Sm and the clock frequency signal Sc are extracted by the high-pass filter 22, a signal having a low noise level and high purity can be extracted. explain. The fifth embodiment corresponds to the sixth invention of the present application.
[0139]
FIG. 7 is a block diagram showing the fifth embodiment. The basic configurations of the simplified base station 1 and the centralized base station 2 are substantially the same as those in the fourth embodiment, but are modulated and output from the remodulator 13 to the centralized base station 2 as shown in FIG. A low-pass filter 25 for extracting a low-frequency component from the digital radio information signal, and a variable-frequency oscillator 21a that oscillates the oscillation frequency signal Sm56 and a variable-frequency oscillator 21b that oscillates the clock signal Sc60. The transmission output is added by the adder 15 and then converted into an optical signal by the electro-optical converter 11 m and transmitted to the centralized base station 2.
[0140]
The simple base station 1 is newly provided with a band pass filter 24. The band pass filter 24 is a filter for extracting a band component from an optical signal converted into an electric signal by the opto-electric converter 12s and output, and for removing a harmonic component. is there. The signal from which the harmonic component is removed is used as a clock signal Sc of the A / D converter 10 and the D / A converter 18, and the mixer 8t, 8r is provided with the output of the high-pass filter 22.
[0141]
That is, the high-pass filter 22 of the simple base station 1 extracts the high-frequency component of this signal from the optical signal converted into the electric signal by the photoelectric converter 12s and output, thereby generating the oscillation frequency signal Sm. Is supplied to the mixers 8t and 8r and used as a local signal for frequency down-conversion or frequency up-conversion.
[0142]
The operation of the system having such a configuration will be described. In the centralized base station 2, the digital radio information signal 55 output from the modem 13 is added to the oscillation frequency signal Sm56 from the variable frequency oscillator 21a controlled by the controller 14. The adder 15 superimposes the clock signal Sc60 from the variable frequency oscillator 21b.
[0143]
Usually, the harmonics of the digital wireless information signal 55 appear greatly in a wide range. In particular, the centralized base station 2 oversamples an analog signal, which is a radio signal, converts it to a digital signal and transmits it to the simplified base station 1 side, so that the information capacity tends to increase and the harmonics are proportional to the capacity. And spread to the high range.
[0144]
As shown in FIG. 8A, when the oscillation frequency signal Sm56 or the clock signal Sc60 overlaps the harmonic component of the digital wireless information signal 55, noise is added to the oscillation frequency signal and the clock signal, so that the SN ratio is deteriorated. This leads to an increase in noise during frequency conversion and malfunction of the A / D converter 10 and D / A converter 18.
[0145]
For this reason, the digital radio information signal 55 is transmitted through the low-pass filter 25 that removes harmonic components, and then superimposed on the oscillation frequency signal Sm56 and the clock signal Sc60.
[0146]
Since the low-pass filter 25 is inserted to remove harmonics, the oscillation frequency signal Sm56 and the clock signal Sc60 do not overlap with the harmonic components of the digital radio information signal 55 as shown in FIG. Therefore, when transmitting a large-capacity digital wireless information signal 55, the oscillation frequency signal Sm56 and the clock frequency signal Sc60 can be superimposed without worrying about harmonics.
[0147]
Then, by removing the harmonic components, when the oscillation frequency signal Sm56 and the clock signal Sc60 are taken out by the high-pass filter 22 and the band-pass filter 24 on the simple base station 1 side, the noise level is lowered, and the purity is reduced. A high signal can be extracted.
[0148]
Each of the above embodiments has a configuration in which an A / D converter and a D / A converter are provided on the simple base station side, but the A / D converter and the D / A converter are on the central base station side. The simple base station side can be configured to transmit and receive only analog wireless information signals, and the simple base station can be further simplified to reduce the size and cost. The embodiment will be described next.
[0149]
(Sixth embodiment)
The sixth embodiment corresponds to the seventh invention of the present application. As shown in FIG. 9, the A / D converter and the D / A converter are provided on the central base station side, and on the simple base station side. Only analog radio information signals are transmitted and received.
[0150]
In FIG. 9, 1 is a simple base station that performs radio communication with terminals in a radio zone, 2 is a centralized base station, and the simple base station 1 divides the closed space into small cell areas and each of these cells. A simple base station 1 is installed for each area to serve as a service area. A plurality of such simple base stations 1 are taken as a group, and a centralized base station 2 that performs centralized control for the simple base station group is provided. The simple base station 1 and the centralized base station 2 are connected by an optical fiber 3, and wireless information Signals are converted into optical signals for transmission.
[0151]
The configuration will be described in detail. The simple base station 1 includes an antenna 4, a circulator 5, a low noise amplifier 6, mixers 8t and 8r, a low-pass filter 9, an electric-optical converter (E / O) 11s, an optical-electric converter ( O / E) 12 s, a band-pass filter 17, high-pass filters 19 and 22, and a power amplifier 20.
[0152]
Among these, the antenna 4 is for transmitting and receiving radio waves, the circulator 5 sends a transmission signal from the transmission system to the antenna 4, and sends a reception signal from the antenna 4 to the reception system. This is a path switcher with directionality for path switching.
[0153]
The low noise amplifier 6 is an amplifier that amplifies the received signal from the antenna 4 input via the circulator 5, and the mixer 8 r multiplies the signal output from the amplifier 6 with the signal from the high pass filter 22. The frequency is down-converted. The low-pass filter 9 is a filter for image removal that extracts a low-frequency component of the signal frequency-converted by the mixer 8r and gives it to the electro-optical converter 11s.
[0154]
The optical-electrical converter (O / E) 12s is for converting an optical signal sent from the centralized base station 2 through the optical fiber 3 into an electrical signal. The high frequency component of the signal is extracted, and the oscillation frequency signal Sm is extracted by passing through the filter 22. The oscillation frequency signal Sm is used as a local signal for frequency down-conversion or frequency up-conversion by being supplied to the mixers 8r and 8t.
[0155]
The electro-optical converter (E / O) 11 s is for converting the analog reception signal output from the low-pass filter 9 into an optical signal and sending it to the optical fiber 3.
[0156]
The band-pass filter 17 extracts a band component from the output of the optical-electrical converter (O / E) 12s, and extracts a radio information analog signal. The mixer 8t multiplies the oscillation frequency signal Sm output from the high-pass filter 22 with the band component signal (radio information analog signal) output from the band-pass filter 17, and performs frequency up-conversion. It is an image removal filter that removes noise in the frequency up-converted signal. The power amplifier 20 is an amplifier that amplifies the output from the high-pass filter 19 for wireless transmission and sends it to the circulator 5.
[0157]
Further, as shown in FIG. 9, the centralized base station 2 includes an electrical-optical converter (E / O) 11m, an optical-electrical converter (O / E) 12m, a modulator / demodulator 13, a centralized base station controller 14, An adder 15, variable frequency oscillators 21a and 21b, a D / A converter 26, and an A / D converter 27 are provided.
[0158]
Here, the electrical-optical converter (E / O) 11m is for converting an electrical signal into an optical signal and sending it to the optical fiber 3, and the optical-electrical converter (O / E) 12m is The D / A converter 26 converts an optical signal transmitted from the optical fiber 3 into an electrical signal. The D / A converter 26 converts a digital wireless information signal output from the demodulator 13 into an analog wireless information signal. Is. The variable frequency oscillator 21b oscillates the oscillation frequency signal Sm56 under the control of the controller 14, and the variable frequency oscillator 21a oscillates the clock signal Sc60 under the control of the controller 14. The adder 15 adds the oscillation frequency signal Sm56 and the clock signal Sc60 to the output of the D / A converter 26, and outputs the result. The electro-optical converter 11m outputs the output of the adder 15. Is converted into an optical signal and sent out to the optical fiber 3.
[0159]
The optical-electrical converter 12m converts a signal transmitted through the optical fiber 3 into an electrical signal. The A / D converter 27 converts the output signal from the optical-electrical converter 12m into a digital signal. This is converted into a signal and passed to the modem 13. In this system, the D / A converter 26 and the A / D converter 27 are configured to operate according to the clock signal Sc60 output from the variable frequency oscillator 21a.
[0160]
Further, the modem 13 modulates an information signal transmitted from the communication partner into a digital radio information signal and outputs it to the D / A converter 26, and also an opto-electric converter (O / E). ) A demodulated signal obtained by demodulating an electrical signal converted and output at 12 m into a digital signal by the D / A converter 27 is output.
[0161]
The modulator / demodulator 13 is a modulator / demodulator whose function can be changed by software, and includes a software control unit 115 and a digital signal processing unit (DSP) 114, and the modulation / demodulation of the digital signal processing unit 114 by the software control unit 115. Function can be changed.
[0162]
In this system, the radio signal handled by the simple base station 1 is analog, and the digital signal is handled only by the centralized base station 2.
[0163]
The operation of the simple base station 1 and the central base station 2 will be described in detail. In the central base station 2, the digital radio information signal output from the modem 13 is converted into an analog signal by the A / D converter 26.
[0164]
An oscillation frequency signal Sm56 from the variable frequency oscillator 21a controlled by the controller 14 is superimposed on the converted analog signal by the adder 15, converted into an optical signal, and transmitted to the simplified base station 1.
[0165]
On the simple base station 1 side, the transmitted optical signal is received, converted into an electrical signal by the optical-electrical converter 12 s, branched, and the wireless information analog signal is branched by the bandpass filter 17, by the highpass filter 22. The oscillation frequency signal Sm56 is extracted.
[0166]
The two extracted signals are input to the mixer 8 and frequency up-converted, and then the image is removed by the high-pass filter 19, and then a radio signal is transmitted from the antenna 4 to the information terminal through the power amplifier 20 and the circulator 5.
[0167]
The radio signal received from the antenna 4 is input to the mixer 8 through the circulator 5 and the low noise amplifier 6, and is output from the oscillation frequency signal Sm (the variable frequency oscillator 21a of the concentrated base station 2) extracted by the high pass filter 22. The frequency is down-converted from the oscillation frequency signal Sm) transmitted through the optical fiber 3.
[0168]
The frequency down-converted signal is sent to the low-pass filter 9 where the image is removed and then sent to the electro-optical converter 11s to be converted into an optical signal and transmitted to the centralized base station 2. .
[0169]
The centralized base station 2 receives this transmitted signal, converts it to an electrical signal by the opto-electric converter 12m, converts it to a digital signal having radio information by the A / D converter 27, and modulates / demodulates it. Is input to the device 13.
[0170]
At this time, the A / D converter 27 and the D / A converter 26 in the centralized base station 2 use the output frequency signal Sc from the variable frequency oscillator 21b controlled by the controller 14 as a clock signal. By changing the clock signal Sc, the conversion band of A / D and D / A is changed.
[0171]
In general, frequency down-conversion and frequency up-conversion are often performed on the simple base station 1 side. This is because the bands of the optical-electrical converters 12s, 12m and the electric-optical converters 11s, 11m are: This is because the frequency band is lower than the frequency band of the radio signal. In such a case, it is necessary to perform frequency conversion on the simple base station 1 side.
[0172]
However, if the system includes a radio signal frequency band within the bands of the optical-electrical converters 12s and 12m and the electrical-optical converters 11s and 11m, the simplified base station 1 does not perform frequency conversion. In addition, it is only necessary to perform frequency conversion within the conversion band of the A / D converter and the D / A converter on the concentrated base station 2 side.
[0173]
The present embodiment assumes such a system. Therefore, an A / D converter 27 and a D / A converter 26 are provided on the central base station 2 side, and these converters 26 are provided on the central base station 2 side. , 27, it is sufficient to perform frequency conversion within the conversion band, so that the configuration of the simplified base station 1 is further simplified, and the change of the used frequency only needs to be dealt with on the concentrated base station 2 side. An inexpensive system that can easily cope with frequency changes can be constructed with a simple configuration.
[0174]
In each of the above embodiments, the digital transmission on the optical fiber 3 has a noise tolerance of the optical signal, and the transmission distance between the simple base station 1 and the concentrated base station 2 can be increased. The electro-optical converters 11s and 11m require a light source. However, since the non-linear characteristic does not matter as a light source used for this, even a low-priced and low-priced inexpensive laser element can be used sufficiently. It is. Therefore, it is possible to reduce the cost of the simple base station 1 as a whole.
[0175]
However, when the capacity of a radio signal to be transmitted / received is relatively large, for example, when the capacity is 155 [Mb / s], the signal after frequency down-conversion is sampled four times and A / D with an amplitude of 8 [bit] If conversion is performed, the digital signal capacity is 4.96 [Gb / s]. That is, if the capacity of the wireless information signal is large to some extent, a very high speed A / D converter 10 and high speed electro-optical converters 11s and 11m are required, and it is difficult to configure the simple base station 1 at low cost. Become.
[0176]
Therefore, an embodiment that can cope with this will be described below.
[0177]
On the other hand, in the case of analog transmission after the seventh aspect of the invention, for radio signals having a high frequency band and a large signal capacity, signal processing for frequency conversion for inclusion in the bands of the electro-optical converters 11s and 11m. Therefore, the signal band is not widened. However, in the case of analog transmission, it cannot be said that the noise tolerance of the optical signal is good, so the transmission distance between the simple base station 1 and the centralized base station 2 cannot be as long as digital transmission. In particular, since the third-order distortion due to the nonlinear characteristics of the laser elements in the electro-optical converters 11s and 11m is greatly affected, it is necessary to use an analog laser with low distortion and high price. As a method for accommodating the simplified base station 1, time division multiplexing or wavelength multiplexing is usually used in digital transmission. Time-division multiplexing is complicated to control, such as timing synchronization of each simple base station 1 in consideration of transmission time in the optical fiber 3. In wavelength multiplexing, it is necessary to control the wavelength so that beat noise due to the light source wavelength of each simple base station 1 does not occur. On the concentrated base station 2 side, the wavelength is separated and light is received for each simple base station 1. There is a need to.
[0178]
On the other hand, wavelength transmission is usually used in analog transmission, and it is necessary to control the wavelength as in digital transmission. However, the wavelength is separated on the centralized base station 2 side by subcarrier multiplexing the wireless information signal. Therefore, it is possible to receive optical signals for each simple base station 1 at a time, and the configuration of the optical / electrical conversion unit 12 of the concentrated base station 2 can be simplified.
[0179]
As described above, regarding the analog transmission and the digital transmission of the wireless information signal to the optical fiber 3, it is generally difficult to obtain superiority or inferiority, the signal capacity of the wireless information signal, the number of samples of the wireless information signal necessary for modulation / demodulation, and the quantization rate , A / D converter 10, D / A converter 18, laser characteristics of electro-optical converters 11s, 11m, transmission distance between simple base station 1 and centralized base station 2, accommodation method of simple base station 1, etc. It is important to determine the transmission form in consideration of the above.
[0180]
Next, another example will be described in which various wireless signals can be transmitted and received while achieving energy saving and cost reduction.
[0181]
(Seventh embodiment)
In the seventh embodiment, the wireless signal transmitter / receiver 602 provided for the wireless signal optical transmission has two types of wireless signal transmitters / receivers for wideband wireless signals and narrowband wireless signals, while saving energy and reducing costs. This is designed to be compatible with signal transmission and reception, and will be described in detail below.
[0182]
FIG. 10 shows a seventh embodiment of the present invention. 10 shows a wireless communication base station apparatus corresponding to claim 10, and a portion surrounded by a broken line 601 is a wireless signal optical transmission receiver corresponding to claim 4, and is surrounded by a broken line 602. The portion shows a transceiver for transmitting radio signal light corresponding to claim 8.
[0183]
In the figure, reference numeral 602 denotes a transmitter / receiver for wireless signal light transmission, and reference numerals 605a to 605n denote base stations. Reference numeral 606 denotes a base station antenna, 607 an antenna duplexer, 608 an electro-optical converter (E / O), 609 an optical-electric converter (O / E), 610 an optical coupler or filter, 633 Is an optical amplifier, 634 is an optical-electrical converter (O / E), 631 is an optical amplifier, 611 and 632 are optical filters, 630 is an optical fiber, 612 and 629 are optical amplifiers, and 613 is an optical-electrical converter (O / E), 628 is an electro-optical converter (E / O), 614 is a distributor, 615 and 616 are filters, 618 and 699 are distributors, 619 and 621 are broadband wireless receivers, and 620 and 624 are narrowbands Radio receivers 627, 623 and 624 are hybrid circuits, and 625 and 626 are filters.
[0184]
Among these, the broadband wireless transmitter 621 generates a plurality of types of broadband wireless signals (radio signals belonging to band # 4, band # 5, and band # 6 in the example of FIG. 10), and narrowband wireless transmission. The device 622 generates a plurality of types of narrowband wireless signals (wireless signals belonging to band # 1, band # 2, and band # 3 in the example of FIG. 10).
[0185]
Also, the hybrid circuits 627, 623, and 624 synthesize multi-system input signals, and the hybrid circuit 623 uses the band # 4, band # 5, and band # 6 output from the broadband wireless transmitter 621. The hybrid circuit 624 combines the radio signals belonging to the band # 1, the band # 2, and the band # 3 output from the narrowband radio transmitter 622. The hybrid circuit 627 combines the signals output from the filters 625 and 626 and outputs the combined signals to the electro-optical converter 628.
[0186]
The electro-optical converter 628 converts the output signal of the hybrid circuit 627 into an optical signal and outputs the optical signal to the optical amplifier 629. The optical amplifier 629 optically amplifies the optical signal from the electro-optical converter 628. Output to the optical fiber 630 serving as a transmission line.
[0187]
The optical amplifier 612 receives an optical signal transmitted through an optical fiber 611 serving as a transmission path, optically amplifies it, and supplies it to an optical-electrical converter 613. The optical-electrical converter 613 The optically amplified optical signal is converted into an electric signal and supplied to the distributor 614.
[0188]
The distributor 614 is a circuit for branching the electric signal into two branches, and one of the two branches is supplied to the filter 615 and the other is supplied to the filter 616 to extract a signal component in a desired band. The distributor 618 distributes the output of the filter 615 to a plurality of wideband wireless receivers 619, and the distributor 619 distributes the output of the filter 616 to a plurality of narrowband wireless receivers 620.
[0189]
A plurality of wideband wireless receivers 619 receive and process any one of the wireless signals belonging to band # 4, band # 5, and band # 6, which are distributed wideband wireless signals, and the narrowband wireless receiver 620 One of the wireless signals belonging to band # 1, band # 2, and band # 3, which is the distributed narrow band radio signal, is received and processed.
[0190]
The base stations 605a to 605n are distributed and connected to the optical fibers 611 and 630, respectively, so that signals can be exchanged with the transceiver 602 for wireless signal light transmission via these optical fibers 611 and 630. It has become.
[0191]
Optical fibers 611 and 630 are provided with optical couplers or optical filters 610 and 632 at intermediate points, that is, at the positions where the base stations 605a to 605n are arranged, and in the optical fiber by long-distance optical transmission. In order to cope with the attenuation of the generated optical signal, optical amplifiers 631 and 617 are appropriately attached.
[0192]
Thus, the base stations 605a to 605n are optically coupled to the optical fibers 611 and 630 via the optical couplers or optical filters 610 and 632, respectively.
[0193]
Each of the base stations 605a to 605n includes an antenna 606, an antenna duplexer 607, an optical-electrical converter 634, an electrical-optical converter 608, and optical amplifiers 609 and 633. The antenna duplexer 607 isolates transmission / reception signals, and an antenna 606 that transmits / receives radio signals is connected to the antenna duplexer 607.
[0194]
The optical amplifier 633 amplifies the optical signal in the optical fiber 630 captured by the optical coupler or the optical filter 632, and the opto-electric converter 634 converts the optical signal amplified by the optical amplifier 633 into an electrical signal. After the converted electrical signal is amplified, it is transmitted to the antenna 606 via the antenna duplexer 609, and transmitted to the outside as a radio signal.
[0195]
The electro-optical converter 608 converts the received radio signal received by the antenna 606 and obtained through the antenna duplexer 607 into an optical signal. The optical amplifier 609 amplifies the optical signal to generate an optical coupler. Or it sends out to the optical filter 610.
[0196]
In the radio communication base station apparatus having such a configuration shown in FIG. 10, five frequency bands as shown by a graph 603 showing the frequency spectrum distribution, that is, band # 1, band # 2, band # 3, band # 4, band # 4 5. It has a function of transmitting and receiving signals in band # 6.
[0197]
In general, in the case of personal communication in which a terminal used by a user and a simple base station represented by a radio communication base station apparatus according to the present invention communicate, generally a communication system using a higher frequency band as a carrier wave transmits / receives a broadband signal. There is a peculiar property to do.
[0198]
Utilizing this unique property, the entire band # 1 to band # 6 is divided into two by a certain frequency fb1 (604) and transmitted / received by a transceiver according to the bandwidth of the signal transmitted in each band group. Can be considered.
[0199]
Next, the operation of the system having the above-described configuration will be described. In the wireless communication base station apparatus of the embodiment of FIG. 10, a communication system using three bands of band # 1, band # 2, and band # 3 uses a narrowband wireless receiver 622 and a narrowband wireless transmitter 621. A communication system that performs transmission and reception and uses three bands of band # 4, band # 5, and band # 6 performs transmission and reception using a broadband wireless receiver 620 and a broadband wireless transmitter 619.
[0200]
For example, as shown in FIG. 11, 900 [MHz] band and 1.5 [GHz] band used for digital cellular, 1.9 [GHz] band used for PHS, and 5 [GHz] band used for high-speed LAN. 20 [GHz] band and 38 [GHz] band used for LMDS (Local Multipoint Distribution System), high-speed WLL (Wireless Local Loop), etc., in order of band # 1, band # 2, band # 3, band # 4 Considering band # 5 and band # 6, when performing transmission / reception of these systems, band # 1 to band # 3 transmit a narrowband signal of 1 [MHz] at most per frequency channel, A wideband signal exceeding 1 [MHz] is transmitted from the band # 4 to the band # 6.
[0201]
Therefore, an appropriate frequency is selected as fb1 in consideration of the characteristics of the filter to be used between the 1.9 [GHz] band and the 5 [GHz] band, the transmission power and reception power in each band, and the dynamic range thereof. It is possible.
[0202]
In addition, it is considered that up to about 25 [Mbps] per frequency channel is likely to be transmitted up to band # 4, whereas a wide band signal exceeding 100 Mbps is often transmitted in bands # 5 and # 6. It is done.
[0203]
Accordingly, an appropriate frequency is selected as fb1 in consideration of the characteristics of the filter to be used between the 5 [GHz] band and the 20 [GHz] band, the transmission power and reception power in each band, and the dynamic range thereof. Alternatively, fb2 may be selected in the same manner, and the entire band # 1 to band # 6 may be divided into three parts using fb1 between the 1.9 [GHz] band and the 5 [GHz] band described above. Conceivable.
[0204]
In addition, considering all cases where band # 1 to band # 6 are all divided or adjacent bands are combined, it is also possible to divide into two or three or four or five.
[0205]
In addition, it is conceivable that the number of divisions and the frequency to be divided differ between the receiver for wireless signal light transmission and the transmitter for wireless signal light transmission. And a clock frequency used for them can be selected.
[0206]
Here, when the clock frequency is selected to be different between the receiver and the transmitter, an effect of reducing mutual interference due to leakage of the clock signal also occurs. Further, when a new wireless communication system is used in the future, the number of divisions, the division frequency, etc. are determined by the positional relationship on the frequency axis of the band, the signal band per frequency channel of the signal transmitted by the new wireless communication system, and the like. Need to be determined.
[0207]
On the other hand, in general, in a high-frequency circuit, it is difficult to improve gain, phase characteristics, in-band deviation, and the like as the ratio band of a target band is larger.
[0208]
Therefore, by dividing the frequency band group having the function of transmitting and receiving into a plurality of parts, and preparing the divided frequency band group that satisfies the required gain and phase characteristics, etc., wireless communication with easier and lower cost An effect is obtained that it is possible to configure a base station device, a radio signal light transmission receiver, and a radio signal light transmission transceiver.
[0209]
<Flow of received signal>
Next, the flow of received signals in the radio communication base station apparatus of the embodiment of FIG. 10 will be described. A plurality of simple base stations 605a,... 605n are distributed to communicate with terminals of the wireless communication system around each. Radio signals from the terminals are received by the respective antennas 606 connected to the simple base stations 605a,... 605n, and an antenna duplexer 607 for isolating the transmission / reception signals (in some communication systems, it may be replaced with a high-frequency switch or the like. ), And after being subjected to amplification or filtering processing if necessary, it is converted into an optical signal by the electro-optical converter 608 and amplified by the optical amplifier 609 if necessary.
[0210]
Here, although all the bands are received by a single antenna 606 having very wide band characteristics, a plurality of transmission / reception characteristics suitable for different bands (or a plurality of bands) as shown in FIG. Using antennas 1101, 1102, 1103, and 1104, using antenna duplexers, amplifiers, filters, and the like as necessary, combining them with a signal combiner 1105, and converting them into optical signals with an electrical / optical converter 608. Is also possible.
[0211]
Further, among the antenna groups attached to the simple base station 605i (i = 1, 2, 3,... N) as shown in FIG. 13, “for 20 [GHz] band” and “for 38 [GHz] band” As described above, a plurality of antennas may be used to cover a certain radio zone. In such a case, it is conceivable to use a simple base station as shown in FIG. 11 for the signal after combining the signals of a plurality of antennas.
[0212]
Further, depending on the band, the signals of a plurality of antennas may be combined (or selected), such as “for 5 [GHz] band” and “for ~ 2.2 [GHz] band” in the example shown in FIG. It is also possible to use a diversity method.
[0213]
In such a case, it is conceivable to use a simple base station as shown in FIG. 11 for the signal after diversity combining (or selection). The optical signal output from the simplified base station 605 is connected to the optical fiber 611 by an optical coupler 610 (which may be replaced with an optical filter). When the transmission distance using the optical fiber 611 is long, it is possible to amplify and shape the optical amplifier 617 or the like as needed during the process.
[0214]
An optical fiber 611 serving as an optical transmission path is connected to a wireless signal light transmission receiver 601 in a wireless signal light transmission transceiver 602.
[0215]
In the wireless signal light transmission receiver 601, first, an optical signal from the optical fiber 611 is amplified by an optical amplifier 612 as necessary, and then regenerated and converted into an electrical signal by an optical-electric converter 613. The electric signal is branched by a distributor (R1) 614 and input to a filter (R1) 615 and a filter (R2) 616, respectively.
[0216]
The output of filter (R1) 615 is distributed by distributor (R2) 618 and input to one or more broadband wireless receivers 619. Further, the output of the filter R2 (616) is distributed by a distributor (R2) 699 and input to one or a plurality of narrowband radio receivers 620.
[0217]
As a characteristic of the filter (R1) 614, a high-pass filter (HPF) having a characteristic of sufficiently attenuating a frequency component in the band # 3 or lower, or each frequency component in the band # 1, the band # 2, and the band # 3 is sufficient. A band rejection filter (BRF) having the characteristic of attenuating the frequency band, or a band having a characteristic of sufficiently attenuating other frequency components without attenuating the frequency components of band # 4, band # 5, and band # 6 as much as possible. A pass filter (BPF) or the like can be considered.
[0218]
As a characteristic of the filter (R2) 616, a low-pass filter (LPF) having a characteristic of sufficiently attenuating frequency components of band # 4 or higher, or each frequency component of band # 4, band # 5, and band # 6 is sufficient. A BRF having a characteristic of attenuating the frequency band or a BPF having a characteristic of sufficiently attenuating the other frequency components without attenuating the frequency components of the band # 1, the band # 2, and the band # 3 as much as possible.
[0219]
By giving such characteristics, interference signals existing in bands other than the reception target at the time of reception by the wideband wireless receiver 619 and the narrowband wireless receiver 620 are reduced, respectively. There is an advantage that characteristics of a digital filter and an analog filter for obtaining selectivity can be simplified. Moreover, the effect that the reception performance in each receiver improves is also acquired.
[0220]
In the wireless signal light transmission receiver 601, it is conceivable that software wireless devices that can support at least two or more of the wireless communication systems as described above are arranged.
[0221]
It is possible to flexibly cope with traffic fluctuations of each system. For example, a set of radios can handle both cellular with a traffic peak in the evening and PHS with a peak in the evening.
[0222]
However, when transmitting / receiving a broadband wireless signal as compared with the case of transmitting / receiving only a narrowband wireless signal, the A / D converter and the D / A converter need to be high speed, which increases power consumption. A point is created. A software defined radio for a narrow band signal such as cellular requires a relatively low sampling frequency of the A / D converter and the D / A converter, but LMDS and the like need to have a wide band and a high sampling frequency. Therefore, if all software defined radios are compatible with LMDS, the configuration becomes expensive. When a software defined radio is used for such a broadband wireless receiver 619 or a narrowband wireless receiver 620, the following effects are further produced.
[0223]
First, when there is no distributor 614 and filter R2 (616), the narrowband wireless receiver 620 needs to remove interference wave components existing in the band # 4, the band # 5, and the band # 6. It is necessary to realize a filter characteristic for attenuating the noise by software on a DSP (digital signal processor).
[0224]
In order to realize this, it is necessary to make the sampling frequency of the digital signal sufficiently higher than twice the highest frequency among the interference waves. Accordingly, digital signal processing at a very high frequency is required, and as a result, all the broadband wireless receivers 619 are arranged as shown in FIG.
[0225]
On the other hand, when the distributor 614 and the filter (R2) 616 are used, since the interference wave does not exist in the band # 4 and the frequency above it, the sampling frequency of the digital signal can be lowered. Accordingly, the narrowband wireless receiver 620 can be configured with low operating frequency, low cost, and low power consumption.
[0226]
Also, when there is no distributor 614 and filter (R1) 615, the broadband wireless receiver 619 needs to remove the interference wave components existing in the bands # 1, # 2, and # 3. It is necessary to realize the filter characteristic to be attenuated by software on the DSP.
[0227]
On the other hand, when the distributor 614 and the filter (R1) 615 are used, since the interference wave does not exist in the band # 3 and lower frequencies, the required filter characteristic is the band # 4. Since the required wave component of the band # 5 and band # 6 can be removed, the specification of the filter characteristics is reduced correspondingly, and the number of digital filter stages and the format are simplified. Can do.
[0228]
As described above, in order to transmit / receive all bands from band # 1 to band # 6 using a software defined radio, the signal is once branched into a plurality of signals, and band limitation is applied to the branched signal. As a whole, the receiver for wireless signal light transmission can be constructed at a low cost and with low power consumption. Even when a software defined radio is used, it is conceivable to use an analog filter in order to obtain selectivity for removing frequency interference. However, by adopting the configuration of this embodiment, the characteristics of the analog filter can be used. Thus, it is possible to obtain an effect that the cost can be reduced.
[0229]
<Flow of transmission signal>
Next, the flow of transmission signals in the radio communication base station apparatus of the embodiment of FIG. 10 will be described.
[0230]
The broadband wireless transmitter 621 generates radio signals belonging to band # 4, band # 5, and band # 6. The narrow band radio transmitter 622 generates radio signals belonging to band # 1, band # 2, and band # 3.
[0231]
In general, the narrow-band wireless transmitter 622 has a lower price and lower power consumption than the broadband wireless transmitter 621, and the number and ratio of both are determined according to the predicted demand of the wireless system. Compared to the case where the narrow band wireless transmitter 622 is not used at all and the wide band wireless transmitter 621 is used as a whole, the price can be reduced and the power consumption can be reduced.
[0232]
The outputs of the plurality of broadband wireless transmitters 621 and the outputs of the plurality of narrowband wireless transmitters 622 are input to the hybrid circuits 623 and 624 that synthesize the respective signals, and then necessary for harmonic removal, waveform shaping, etc. Accordingly, the signal passes through the filter (T1) 625 and the filter (T2) 626, and is input to the hybrid circuit 627 for synthesizing the respective signals and synthesized.
[0233]
In the embodiment of FIG. 10, three hybrid circuits are used. However, if the filter (T1) 625 and the filter (T2) 626 are not required, the number of hybrid circuits necessary for at least one signal synthesis is used. You may comprise with a circuit.
[0234]
The combined electric signal is converted into an optical signal by an electric-optical converter 628, amplified as necessary by an optical amplifier 629, and transmitted to a plurality of simple base stations 605 through an optical fiber 630. When the transmission distance using the optical fiber 630 becomes a long distance, amplification and shaping with an optical amplifier 631 or the like may be considered as needed during the process.
[0235]
An optical signal transmitted through the optical fiber 630 and partially or entirely extracted from each simple base station 605 by an optical coupler or optical filter 632 is input to each simple base station 605a,.
[0236]
In the simple base stations 605a,... 605n, the optical amplifier 633 amplifies as necessary, and the optical-electrical converter 634 converts it into an electrical signal. The converted electrical signal is amplified and shaped as necessary, and is transmitted from the antenna 606 to the air through the antenna duplexer 607 as a radio signal.
[0237]
In the seventh embodiment described above, energy saving and cost reduction are achieved by providing two types of wireless signal transmitters / receivers for the wireless signal light transmission transmitter / receiver 602 for wideband wireless signals and narrowband wireless signals. However, it was designed to be compatible with various wireless signal transmission and reception.
[0238]
However, in the configuration of FIG. 10 described above, an optical signal is converted into an electric signal, then the electric signal is distributed, and the electric signals are combined and then converted into an optical signal. It is also possible to adopt a configuration in which each signal is input to a filter after being distributed as it is, or an optical signal is combined with an optical coupler or an optical filter after the electrical signal output of each filter is converted into an optical signal. Therefore, the example will be described as an eighth embodiment.
[0239]
(Eighth embodiment)
FIG. 15 shows an eighth embodiment. In the configuration of FIG. 15, the radio signal light transmission / reception device 602 in the configuration of FIG. 10 is replaced with the optical-electrical converter 613 and the electrical-optical that are in the optical amplifiers 612 and 629 stages at the entrance and exit of the optical fibers 611 and 630. The converter 628 is abolished, and instead, an optical-electric converter 613a is disposed between the distributor 614 and the filter 615, an optical-electric converter 613b is disposed between the distributor 614 and the filter 616, and The distributor 614 is an optical distributor.
[0240]
Further, the hybrid circuit 627 in the configuration of FIG. 10 is abolished, an optical coupler or optical filter 650 is provided instead, and this is connected to the optical amplifier 629, and between the filter 626 and the optical coupler or optical filter 650, electrical − An optical converter 628 b is provided, and an electro-optical converter 628 a is provided between the filter 625 and the optical coupler or optical filter 650.
[0241]
In this configuration, after distributing the optical signal as it is, each signal is input to a filter, or the electrical signal output of each filter is converted into an optical signal and then the optical signal is synthesized by an optical coupler or an optical filter. It is a configuration.
[0242]
In general, an optical distributor / combiner is smaller than that of an electric signal, and the apparatus can be miniaturized. When the transmitted signal has a wide band, the electric signal distributor / synthesizer may have a large loss, so that the configuration of the entire apparatus becomes easy. On the other hand, when the electric signal is distributed after being converted into an electric signal, or when the electric signal is converted into an optical signal after the electric signals are combined, an expensive optical / electrical conversion device or an associated electric signal filter is used. The number of impedance matching circuits can be reduced, and an electrical signal distributor / combiner that is relatively cheaper than an optical distributor / combiner can be used, thereby reducing the cost of the apparatus. There is.
[0243]
In the above-described embodiment, the software defined radio is also used for transmitting and receiving a broadband wireless signal. However, as described above, the power consumption of this portion is large. Therefore, by configuring this part with a normal radio circuit, it is conceivable to reduce power consumption, although the degree of freedom of signals that can be received is reduced.
[0244]
In the embodiment described above, the entire frequency is divided into two, but the same effect can be obtained even if the number of division is three or more. The same applies to the embodiments described below. Further, in the embodiment described above, a plurality of simple base stations are accommodated in a bus-type architecture from a radio signal light transmission transceiver, but not limited to a bus type, a star type or a loop type, any of these It goes without saying that the same embodiment can be applied even when an architecture by a combination of the above is used.
[0245]
In the case of a configuration using different antennas for different frequency bands (or groups) like the antenna group shown in FIG. 13 instead of using a single broadband antenna, as shown in FIG. It is conceivable that signals in the respective frequency bands (or groups thereof) are exchanged with the antennas 1101, 1102, 1103, and 1104 using a hybrid circuit 1105, a distributor 1106, a filter 1107, an amplifier, and the like, and transmitted and received.
[0246]
Now, due to limitations on characteristics of elements such as LD (laser diode) and external modulator as a light source used in the radio communication base station apparatus and PD (photodiode) as a light receiving element, individual simple base stations 605a,. Therefore, it is necessary to perform frequency conversion on the downlink signal, the uplink signal, or both the downlink signal and the uplink signal.
[0247]
FIG. 16 shows an example of frequency arrangement for optical SCM transmission for accommodating a simple base station that performs such frequency conversion. For example, in the band # 1, control is performed so that frequency channels are not overlapped in the entire radio communication base station apparatus, and frequency conversion is not performed. Further, for example, in the band # 2 to the band # 6, frequency channels are freely selected in each simple base station regardless of the frequency channels used by other simple base stations.
[0248]
Further, for example, in band # 2, frequency conversion is not performed for only one simple base station band, and frequency conversion is performed in other simple base stations. Further, for example, in the band # 3 to the band # 6, frequency conversion is performed in all the simple base stations. In addition, as shown in FIG. 16, a local CW (Continuous Wave) signal, or a CW signal for input to a multiplier, upconverter, downconverter, etc. that generates a local signal, or the frequency of the local signal. It is also conceivable to transmit a reference pilot CW (Continuous Wave) signal for giving a highly stable standard to a simple base station from a radio signal light transmission transceiver.
[0249]
It should be noted that the CW signal is often capable of a higher modulation frequency than the modulation signal, and may be arranged at a higher frequency than the signal for information transmission.
[0250]
In this way, the frequency arrangement and bandwidth as the original radio wave, bandwidth that can be modulated depending on the frequency characteristics of TDD (Time Division Duplex) or FDD (Frequency Division Duplex), LD, external modulator, PD, etc. , And so on, so that frequency overlap does not occur, and when selecting a desired band with a filter in a simple base station, the characteristics of the filter should be as easy as possible. It is conceivable to arrange the frequencies with an appropriate interval.
[0251]
Further, in the simple base station 605 that performs frequency conversion in this way, as shown in FIGS. 17, 18, and 19, a part of the configuration of FIG. 12 is changed, and a downlink signal, an uplink signal, or a downlink signal is changed. And local signals (LOs) 1301, 1302, 1303 and mixers 1304 for generating local frequencies for both the upstream signal and the upstream signal, as well as multipliers, image frequencies, harmonics, and subharmonics are reduced. It is conceivable to perform frequency conversion using a filter, an amplifier, or the like.
[0252]
In FIG. 17, reference numerals 701, 702, 703, and 704 denote antennas, 607 denotes an antenna duplexer provided for each of the antennas 701, 702, 703, and 704, and 1301, 1302, and 1303 denote LO (local oscillators). 1304, 1305, 1306, 1307, and 1308 are mixers, 705 is a hybrid circuit, 706 is a distributor, 608 is an electrical-optical converter, 634 is an optical-electrical converter 634, and 609 and 633 are amplifiers.
[0253]
In the system of the antenna 701, the received signal is mixed with the local signal of the LO 1301 by the mixer 1305, synthesized with the received signal of another system by the hybrid circuit 705, and sent to the electro-optical converter 708. The mixer 1305 mixes the mixed signal from the mixer 1304, and the hybrid circuit 705 synthesizes the received signal with another system of received signal, and sends it to the electro-optical converter 708. The mixer 1304 has LOs 1302 and 1304. The mixer 1306 mixes the local signal and outputs it to the mixer 1307. The mixer 1306 mixes the output of the photoelectric converter 634 with the distributor 706 and the local signal of the LO 1301 to provide an antenna. 701 and the mixer 1308 is an optical-electrical converter 634. If the output is distributed by the distributor 706 and the local signal of the LO 1302 are mixed and given to the antenna 702, etc., for both the downstream signal and the upstream signal, if necessary, In this configuration, local frequency signals from LO (local oscillators) 1301, 1302, and 1303 are mixed and frequency-converted by mixers 1304 to 1308.
[0254]
18 removes the mixers 1304, 1305, and 1307 and the LO 1303 from the configuration of FIG. 17, and in each system of the antennas 701 to 704, the received signal is not subjected to frequency conversion, and the hybrid circuit 705 performs other conversion. In the transmission system, the mixer 1306 distributes the output of the optical-electrical converter 634 by the distributor 706, and the local signal of the LO 1301 is combined with the received signal of the system and sent to the electrical-optical converter 708. And the mixer 1308 is configured to mix the output of the photoelectric converter 634 by the distributor 706 and the local signal of the LO 1302 and to supply to the antenna 702. For example, the local signal from the LO (local oscillator) The number of signals and the mixer and mixed to a configuration which is adapted to frequency conversion.
[0255]
In addition, the configuration of FIG. 19 is the opposite, and the frequency conversion is not performed on the downstream signal, and only the upstream signal is mixed by the local frequency signal from the LO (local oscillator) and the mixer as necessary. Thus, the frequency is converted.
[0256]
Here, in the frequency arrangement of FIG. 16, in the case of a TDD system such as band # 2 or band # 5, the frequency arrangement for optical SCM (Sub-Carrier multiplexing) transmission is the same in uplink and downlink, or In the case of an FDD system such as band # 4, if the frequency arrangement for optical SCM transmission is different in the upstream and downstream as much as the frequency difference in the radio signal, as shown in FIG. The effect that the local signal generating circuit can be shared can be obtained.
[0257]
As described above, in the eighth embodiment, the modification example of the ninth embodiment is shown. Next, the narrowband wireless receiver and the broadband wireless receiver, or a part or all of the components constituting the same can be exchanged with each other so that all or part of the connection terminals for wireless signals, control signals, power supplies, etc. An embodiment in which the cost is reduced and the cost is reduced will be described.
[0258]
(Ninth embodiment)
<Configuration Example 1 in Ninth Embodiment>
FIG. 20 shows a ninth embodiment of the present invention. In this embodiment, a narrowband radio receiver and a wideband radio receiver, or a part or all of the components constituting it, are connected to the main body by a non-fixed connection method that can be exchanged with each other. The present invention is characterized in that all or a part of connection terminals such as a power source are made common.
[0259]
The configuration of FIG. 20 is a configuration in which each wireless receiver receives and processes an upstream signal received and transmitted by the simple base station side into an electrical signal and distributed by the distributor R1. The components that make up each radio receiver are high-frequency analog units, A / D converters, and down-converter FPGAs (FPGAs loaded with digital down-converter software; ICs that can be equipped with other programmable combination / sequential circuits. However, generality is not lost), DSP (digital signal processor) loaded with modulator software, channel decoder software and audio decoder software supporting multi-access method, CPU (processor) loaded with receiver control software, etc. Are the component components, and the radio signal and control signal between them. , Assigned to the predetermined terminal or a pin, such as all or part of the connector and socket interconnection of the power supply or the like, and to be in common between the components used for the component and wideband radio receiver for use in narrow-band radio receiver.
[0260]
As a result, when it is desired to change the function of the wireless device, the function of the wireless device can be easily changed by replacing the component.
[0261]
Note that the connection with the distributor can be switched mechanically using a high-frequency connector or the like. The high-frequency switch SW as shown in FIG. It is also possible to adopt a configuration that can be switched automatically. In addition, with regard to the distributor DIV, it is predicted that the number of distribution will be changed in advance, and a distribution device having a distribution number larger than the initial distribution number is installed, and a termination element is attached or detached as necessary. In order to minimize loss, it is conceivable to change the distributor to one having a different distribution number when changing the configuration.
[0262]
<Configuration example 2 in the ninth embodiment>
FIG. 22 shows another configuration example. The functional block diagram of FIG. 22 shows only the portions of the filters 615 and 616, the distributors 618 and 699, the broadband wireless receiver 619, and the narrowband wireless receiver 621 in the configuration example illustrated in FIG. Further, this configuration is an example of a case where a narrowband radio receiver and a wideband radio receiver are realized by software radios, respectively. Among the examples of software radios shown in FIG. The mutual input / output of the / D converter, FPGA, DSP, and MPU is not shown.
[0263]
In the example of FIG. 22, only the high-frequency analog part of the hardware (hereinafter also referred to as H / W) is different between the two sets of narrowband radio receivers and the two sets of wideband radio receivers, but can be interchanged. It is connected to the main body by a non-fixed connection method, and all or part of connection terminals such as a radio signal, a control signal, an operation clock signal, and a power supply are shared, and the A / D converter and the FPGA have an H / W configuration. Although the same, the operating clock for determining the operating frequency is characterized in that the clock used for the broadband wireless receiver is faster than the clock used for the narrowband wireless receiver.
[0264]
Circuit components that require digital clock signals, such as A / D converters and FPGAs, can be operated at low speed by reducing the clock frequency, even if they are H / W for high-speed operation. The power consumption can be reduced compared with the operation.
[0265]
In this embodiment, as shown in FIG. 22, in the narrowband radio receiver, like the component denoted by reference numeral 1805, the clock terminals of the A / D converter 1804 and FPGA 1803 which are its constituent elements are connected to the clock terminals. From a clock source 1807 that generates a clock with a low frequency, and from a clock source 1806 that generates a clock with a high clock frequency at the clock terminals of the A / D converter and FPGA, which are constituent elements of components of a broadband wireless receiver. The clock signal is supplied to each.
[0266]
A distributor (R1) 1801 connected to the narrowband wireless receiver 1805 is a broadband upstream system, and a distributor (R2) 1802 is a narrowband upstream system.
[0267]
Since the traffic ratio of communication using each band has changed from the state used in this configuration, when the number of narrowband radio receivers is reduced by one and the number of wideband radio receivers is increased by one, for example, it is reduced by one. Assuming that the narrowband wireless receiver is a narrowband wireless receiver component 1805, the connection with the distributor (R2) 1802 connected to the high frequency analog unit 1899 of the narrowband wireless receiver component 1805 is as shown in FIG. In addition, the connection to the distributor (R1) 1801 is changed.
[0268]
However, the high-frequency analog unit 1898 of the narrow-band wireless receiver component 1805 is compatible with a wide-band signal, and is connected to the main body by a non-fixed connection method that can be interchanged with the high-frequency analog unit 1898, so that the radio signal It is assumed that all or a part of connection terminals such as a control signal, an operation clock signal, and a power supply are shared.
[0269]
In this way, the connection of the high-frequency analog unit 1899 of the narrowband wireless receiver component 1805 is switched to the broadband distributor. Then, the software loaded in the FPGA 1803 is changed to one having the function of a wideband wireless receiver, and the common clock source 1807 of the low frequency clock connected to the FPGA 1803 and the A / D converter 1804 is used. By changing the connection to the common clock source 1806, the narrowband radio receiver component 1805 can be easily changed in function to a wideband radio receiver component.
[0270]
In this way, the narrowband wireless receiver and the broadband wireless receiver share all or part of the H / W, and depending on the band and frequency of the received signal, the software or program loaded into the PFGA, DSP, and control MPU By changing the operation clock supplied to the A / D converter, PFGA, DSP, and control MPU, it is possible to obtain sufficient reception performance while reducing power consumption during operation as much as possible.
[0271]
Furthermore, regarding the change of the clock, it is only necessary to change the wiring from the common clock source to another existing common clock source by making the connection terminal of the operation clock signal in common, so there is no need to increase the clock source. There is an effect peculiar to the receiver for wireless signal light transmission of the present embodiment that the function as a wireless receiver can be changed. Of course, it may be realized by changing the connection with the clock source using a switch or the like.
[0272]
<Configuration example 3 in the ninth embodiment>
Next, in the example shown in FIGS. 24 and 25, the high-frequency analog unit 1813 of the broadband wireless receiver component 1809 can operate in a wide frequency band and can handle both a broadband wireless signal and a narrowband wireless signal. This is a configuration example.
[0273]
Here, of the broadband wireless receiver components 1808 and 1809, the broadband wireless receiver component 1809 has a high-frequency analog unit 1813 that can operate in a wide frequency band and can handle both a broadband wireless signal and a narrowband wireless signal. Adopted.
[0274]
While the demand for broadband wireless signals can be met only by the broadband wireless receiver component 1808, the broadband wireless receiver component 1809 uses the low frequency clock for its A / D converter 1817 and FPGA 1818 as shown in FIG. Connected to receive a clock supply from a common clock source 1807 and used for narrowband wireless signals. When the demand for broadband wireless signals has increased and it has become necessary to add broadband wireless receiver components, broadband wireless The receiver component 1809 switches the connection of the A / D converter 1817 and the FPGA 1818 so that the clock is supplied from the common clock source 1806 for the high frequency clock, and switches from the narrowband radio signal to the wideband radio signal. To do.
[0275]
In this case, as shown in FIG. 25, first, a connection is made from a common clock source 1806 connected to the FPGA 1818 and the A / D converter 1817 to another common clock source 1807 using a semiconductor switch or the like. At the same time, the software loaded in the FPGA 1818 is changed to one having the function of a narrowband wireless receiver. Although omitted in the figure, the connection from the distributor to the high frequency analog unit is already described in FIG. As described above, a high frequency switch is used to electrically switch to the broadband system side.
[0276]
By doing so, the broadband wireless receiver can be quickly used as a narrowband wireless receiver, or can be returned to the original state.
[0277]
In the case of this embodiment, it is not necessary to be able to replace modules, but by using the distributor 614, filter 615, and filter 616 in FIG. 10, these are not used as in FIG. As compared with the above, there are effects that input of interference waves can be reduced, reception performance can be improved, and a narrow-band radio receiver can be simplified.
[0278]
Of course, when there is no change in the traffic ratio of communication using each band and it is considered that the demand for broadband wireless signals will not increase over the long term in the future, the broadband wireless receiver component 1809 is configured as shown in FIG. The A / D converter 1817 and the FPGA 1818 are connected so as to receive a clock supply from a common clock source 1807 for a low frequency clock, and the high frequency analog unit 1813 is replaced with a high frequency analog unit 1814 corresponding to a narrowband radio signal. By completely adopting a configuration for a narrow band radio signal, it is possible to easily shift to a configuration and power consumption suitable for the actual situation, and to reduce power consumption.
[0279]
Conversely, as shown in FIG. 24, there are two narrowband radio receiver components and two wideband radio receiver components. From this state, the number of narrowband radio receivers is reduced by one and wideband radio reception is performed. In the case of adding one unit, the connection with the distributor connected to the narrow-band wireless receiver component 1810 is changed, and the high-frequency analog unit 1815 is configured to be compatible with wideband signals (high-frequency analog unit 1816) It replaces with the broadband wireless receiver component 1810 replaced with (FIG. 27).
[0280]
In this way, all or a part of connection terminals such as a radio signal, a control signal, an operation clock signal, and a power source are connected to the main body by a non-fixed connection method that allows the components to be interchanged with the high-frequency analog unit 1815. Are replaced with a high-frequency analog unit 1816 which is shared. Then, the software loaded in the FPGA 1820 of the component is changed to one having the function of a broadband wireless receiver, and the connection between the FPGA 1820 and the common clock source 1807 connected to the A / D converter 1819 is changed to the common clock source. Change to connection to 1806. Accordingly, the configuration of FIG. 24 is changed as shown in FIG. 27, and the wireless receiver component for narrow band becomes a component having the function of a wide band wireless receiver, and one wireless receiver component for narrow band is provided. Then, the component having the function of a broadband wireless receiver can be easily transferred to three fixed systems.
[0281]
As described above with reference to FIGS. 22 and 23, the configuration capable of easily changing the combination for the wide band and the narrow band can be realized.
[0282]
Of course, in the case of FIG. 27, since the high-frequency analog unit 1816 can also be used for a narrow band, the connection to the distributor connected to the 1810 can be made even when returning to the function of only the narrow band radio receiver. The software loaded in the FPGA 1820 is changed to the one having the function of a narrowband wireless receiver, and the common clock source 1806 connected to the FPGA 1820 and the A / D converter 1819 is changed. There is also the advantage that this is possible by changing the connection to a connection to the common clock source 1807.
[0283]
<Configuration example 4 in the ninth embodiment>
Next, a configuration example 4 in the ninth embodiment will be described. The example shown in FIG. 28 is an example having two each of the broadband wireless receiver components 1821 and 1822 and the narrowband wireless receiver components 1823 and 1824, respectively. The machine component is not only the high-frequency analog part, but the A / D converter differs between the two narrow-band radio receivers and the two wide-band radio receivers. In this case, all or a part of connection terminals such as a radio signal, a control signal, an operation clock signal, and a power supply are shared.
[0284]
In general, for applications where the system only needs to support narrowband radio signals, the A / D converter circuit may be slow, and thus the clock frequency can be lowered and the A / D converter can be operated at a lower cost. The circuit of the / D converter can be realized, and there is an advantage that power consumption can be suppressed low. Therefore, a clock source having a low clock frequency is used for the A / D converter and the clock terminal of the FPGA of the narrow band radio receiver, and a clock having a high clock frequency is used for the A / D converter and the clock terminal of the FPGA of the wide band radio receiver. A clock signal is supplied from each source.
[0285]
Since the traffic ratio of communication using each band has changed from the operating state in this configuration, it is assumed that the number of narrowband radio receivers is reduced by one and the number of wideband radio receivers is increased by one. In this case, as shown in FIG. 29, the A / D converter 1826 and the high-frequency analog unit 1827 can deal with a broadband signal and can be interchanged with the A / D converter 1826 or the high-frequency analog unit 1827. Replace the A / D converter 1828 and the high-frequency analog unit 1829 that are connected to the main body with a connection method of the type and share all or a part of connection terminals such as a radio signal, a control signal, an operation clock signal, and a power supply, The connection between the FPGA 1825 and the common clock source 1807 connected to the A / D converter 1826 is changed to the connection to the common clock source 1806, and the software loaded in the FPGA 1825 has the function of a broadband wireless receiver. 29 and similar to FIG. 23, the narrowband radio receiver component 1823 To change the connection to the distributor that is continued to the connection to other distributors. By doing in this way, it can change easily to the form which reduces one narrow-band radio receiver and increases one wide-band radio receiver.
[0286]
<Configuration Example 5 in Ninth Embodiment>
Next, a configuration example 5 in the ninth embodiment will be described. In the example of FIG. 30, the high-frequency analog unit 1834, the A / D converter 1835, and the FPGA 1836 of the wireless receiver can operate in a wide frequency band and can handle both a wideband wireless signal and a narrowband wireless signal. It is an example of a structure when it is set to.
[0287]
In this case, as shown in FIG. 31, the connection is changed from the common clock source 1806 connected to the FPGA 1836 and the A / D converter 1835 to another existing common clock source 1807 using a semiconductor switch or the like. The software loaded in the FPGA 1836 is changed to one having the function of a narrowband wireless receiver, and although not shown in the figure, the connection from the distributor to the high frequency analog unit is already described in FIG. By switching electrically using a high-frequency switch, the broadband wireless receiver can be quickly changed to a narrowband wireless receiver and used as a narrowband wireless receiver or returned to its original state.
[0288]
In this case, it is not necessary that the module can be replaced, but by using the distributor 614, the filter 615, and the filter 616 in FIG. 10, as compared with the case where these are not used as shown in FIG. There are effects that the input of interference waves can be reduced, the reception performance can be improved, and the narrow-band radio receiver can be simplified.
[0289]
Of course, when it is considered that the change in the traffic ratio of communication using each band is not temporary but long-term in the future, it is easy to replace the high-frequency analog unit 1834 with a high-frequency analog unit corresponding to a narrow-band radio signal. Low power consumption can be achieved. Conversely, when one narrow band radio receiver is reduced and one wide band radio receiver is added, connection with a distributor connected to the narrow band radio receiver component 1832 is performed as shown in FIG. The FPGA 1339, the A / D converter 1838, and the high-frequency analog unit 1837 are compatible with broadband signals, and can be interchanged with the FPGA 1339, the A / D converter 1838, or the high-frequency analog unit 1837. Replace with FPGA 1342, A / D converter 1841, and high-frequency analog unit 1840 that are connected to the main unit and share all or part of connection terminals such as radio signals, control signals, operation clock signals, and power supplies, and load them into the FPGA The software that has been changed to one with the function of a broadband wireless receiver, FPGA and A / D converter By changing the connection with the connected common clock source 1807 to the connection with the common clock source 1806, it is easy to convert to a configuration in which one narrowband wireless receiver is reduced and one wideband wireless receiver is added. As described in FIGS. 22 and 23, the above can be realized.
[0290]
Of course, in the case of FIG. 32, the FPGA 1342, the A / D converter 1841, and the high-frequency analog unit 1840 can be diverted to a narrow band. The connection with the distributor connected to the receiver component 1832 is changed again, the software loaded in the FPGA 1842 is changed to the one having the function of the narrowband radio receiver, and the FPGA 1842 and the A / D are changed. There is also an advantage that this is possible by changing the connection with the common clock source 1806 connected to the converter 1841 to the connection with the common clock source 1807.
[0291]
In the ninth embodiment, an example of a case where a narrowband wireless receiver and a broadband wireless receiver are realized by a software defined radio is shown. However, in the conventional configuration, that is, on the form, Even when the FPGA and DSP are configured with digital circuits such as conventional gate arrays and ASICs, mechanical switching using a connector, etc., or electrical switching using a switch, or a clock source There is an effect that the configuration can be easily changed by applying the above-described method such as changing the connection frequency and changing the clock frequency to change the operating frequency, or replacing the H / W module. Needless to say.
[0292]
(Tenth embodiment)
FIG. 33 shows a configuration example of a transmitting unit in a transceiver for transmitting radio signal light in the tenth embodiment of the present invention. As in the case of the receiver shown in FIG. 20, the radio signal optical transmission / reception device of this embodiment includes a narrowband radio transmitter and a wideband radio transmitter, or a part or all of the components constituting each other. It is connected to the main body by a non-fixed connection method that can be exchanged, and all or a part of connection terminals such as a radio signal, a control signal, and a power supply are shared.
[0293]
33, as shown in the respective diagrams shown in the ninth embodiment, a D / A converter, a DSP, and an MPU are composed of a high-frequency analog unit in a narrow-band radio transmitter and a wide-band radio transmitter among the transmission units. Only the configuration of the component portion is shown, and the portion showing the non-fixed connection method is omitted and shown as a functional diagram.
[0294]
As shown in the diagrams shown when changing the configuration of the radio receiver in each of the diagrams used in FIGS. 20, 21, and 9th embodiment, the radio circuit shown in FIG. Regarding connection switching, mechanical switching is performed using a high-frequency connector or the like, or electrical switching is performed using a high-frequency switch, or the operating frequency is changed by changing the clock frequency by changing the connection method with the clock source. Alternatively, a configuration in which an H / W (hardware) module is replaced or software is changed can be applied here.
[0295]
Also, power consumption during operation is reduced as much as possible by changing the software or program loaded to the DSP and control MPU and the operation clock to be supplied, depending on the bandwidth and frequency of the signal to be transmitted, with H / W being the same. However, sufficient transmission performance can be obtained.
[0296]
As described above, the simplified base station according to the present invention frequency-converts radio signals with different frequency bands, handles them in the same frequency band, and adjusts the A / D converter, D / D according to the band of each radio signal. In this configuration, the operating band of the A converter can be varied.
[0297]
Therefore, high speed is not required for all the components, and an operation band according to each radio signal can be provided as appropriate, and the power consumption of the simple base station can be reduced. When the power consumption is reduced, the heat sink and backup power supply capacity are also reduced, and the occupied space in the base station can be reduced. That is, the device scale of the simple base station is reduced, and it is easy to install it in a narrow closed space or a utility pole. Therefore, it is easy to install a larger number of simple base stations and to easily expand the coverage area of the wireless communication service. Further, when the power consumption is small, the heat load on the component is also small, so that the durability is improved and the reliability and stability of the simple base station are also improved. In addition, in the entire wireless communication base station including a large number of simple base stations, the power consumption is greatly reduced, and there is an effect that the operation cost of the base station can be suppressed.
[0298]
In particular, in the system of the present invention, the clock signal regenerated from the transmitted digital signal is used as a reference clock for the A / D converter and the D / A converter, and the A / D converter and the D / D according to the signal capacity. By varying the signal bandwidth of the A converter, the control signal related to the signal bandwidth from the concentrated base station side can be reduced, the configuration of the concentrated base station and the simplified base station side can be simplified, and the apparatus scale can be reduced.
[0302]
【The invention's effect】
As described above, the simplified base station according to the present invention frequency-converts radio signals with different frequency bands, handles them in the same frequency band, and adjusts the A / D converter, D / D according to the band of each radio signal. In this configuration, the operating band of the A converter can be varied.
[0303]
Therefore, high speed is not required for all the components, and an operation band according to each radio signal can be provided as appropriate, and the power consumption of the simple base station can be reduced. When the power consumption is reduced, the heat sink and backup power supply capacity are also reduced, and the occupied space in the base station can be reduced. That is, the device scale of the simple base station is reduced, and it is easy to install it in a narrow closed space or a utility pole. Therefore, it is easy to install a larger number of simple base stations and to easily expand the coverage area of the wireless communication service. Further, when the power consumption is small, the heat load on the component is also small, so that the durability is improved and the reliability and stability of the simple base station are also improved. In addition, the power consumption of the entire wireless communication base station including a large number of simple base stations is greatly reduced, and a wireless system can be provided in which the operation cost of the base station can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining the present invention and is a block diagram showing a configuration of a first embodiment of the present invention.
FIG. 2 is a functional block diagram illustrating a principle configuration of a conventional software defined radio for explaining a conventional example.
FIG. 3 is a block diagram for explaining the present invention and showing a second embodiment of the present invention.
FIG. 4 is a diagram for explaining the present invention and showing an optical spectrum in a second embodiment of the present invention.
FIG. 5 is a block diagram for explaining the present invention and showing a third embodiment of the present invention.
FIG. 6 is a block diagram for explaining the present invention and showing a fourth embodiment of the present invention.
FIG. 7 is a block diagram for explaining the present invention and showing a fifth embodiment of the present invention.
FIG. 8 is a diagram for explaining the present invention and showing an optical spectrum in a fifth embodiment of the present invention.
FIG. 9 is a block diagram for explaining the present invention and showing a sixth embodiment of the present invention.
FIG. 10 is a block diagram for explaining the present invention and showing a seventh embodiment of the present invention.
FIG. 11 is a diagram showing frequency bands used for personal communication.
FIG. 12 is a diagram for explaining the present invention and shows a configuration example of a simple base station using a plurality of simple base station antenna groups;
FIG. 13 is a diagram illustrating an example of an antenna group used in a simple base station.
FIG. 14 is a diagram for explaining the present invention and is a block diagram illustrating a configuration example of a radio communication base station apparatus using a broadband radio receiver and a broadband radio transmitter.
FIG. 15 is a block diagram for explaining the present invention and showing an eighth embodiment of the present invention.
FIG. 16 is a diagram for explaining the present invention and shows an example of frequency arrangement for optical SCM transmission for accommodating a simplified base station that performs frequency conversion;
FIG. 17 is a diagram for explaining the present invention and showing an example of a simple base station configuration having a frequency conversion function.
FIG. 18 is a diagram for explaining the present invention and showing another example of a simple base station configuration having a frequency conversion function.
FIG. 19 is a diagram for explaining the present invention and is a diagram illustrating another example of a simple base station configuration having a frequency conversion function.
FIG. 20 is a diagram for explaining the present invention, and is a block diagram for explaining a ninth embodiment of the present invention.
FIG. 21 is a diagram for explaining the present invention and is a configuration diagram showing an example of a connection switching device for a distributor used in a ninth embodiment of the present invention.
FIG. 22 is a diagram for explaining the present invention, and is a block diagram for explaining a ninth embodiment of the present invention.
FIG. 23 is a diagram for explaining the present invention and is a block diagram for explaining a ninth embodiment of the present invention.
FIG. 24 is a diagram for explaining the present invention, and is a block diagram for explaining a ninth embodiment of the present invention.
FIG. 25 is a diagram for explaining the present invention and is a block configuration diagram for explaining a ninth embodiment of the present invention;
FIG. 26 is a block diagram for explaining the ninth embodiment of the present invention, for explaining the present invention.
FIG. 27 is a diagram for explaining the present invention and is a block configuration diagram for explaining a ninth embodiment of the present invention;
FIG. 28 is a diagram for explaining the present invention, and is a block diagram for explaining a ninth embodiment of the present invention.
FIG. 29 is a diagram for explaining the present invention, and is a block diagram for explaining a ninth embodiment of the present invention.
FIG. 30 is a diagram for explaining the present invention, and is a block diagram for explaining a ninth embodiment of the present invention.
FIG. 31 is a diagram for explaining the present invention and is a block configuration diagram for explaining a ninth embodiment of the present invention;
FIG. 32 is a diagram for explaining the present invention and is a block configuration diagram for explaining a ninth embodiment of the present invention;
FIG. 33 is a diagram for explaining the present invention, and is a block diagram for explaining a tenth embodiment of the present invention.
FIG. 34 is a diagram showing a wireless communication base station using a conventional optical fiber.
[Explanation of symbols]
1 ... Simple base station
2 ... Centralized base station
3,611,630 ... Optical fiber
4 ... Antenna
5. Circulator
6 ... Low noise amplifier
7, 21 ... Local oscillator (LO)
8 ... Mixer
9 ... Low-pass filter
10 ... Analog-to-digital converter
11 ... Electric-optical converter
12 ... Opto-electric converter
13 ... Software modem
14 ... Centralized base station controller
15 ... Adder
16 ... Simple base station controller
17 ... Low-pass filter
18 ... Digital-to-analog converter
19, 22 ... high-pass filter
20 ... Power amplifier
23 ... Low-pass filter for band limitation
24. Bandpass filter
25 ... Clock regenerator
26 ... Photo detector
27. Demodulator
41 ... Radio reception signal from the terminal
42 ... Wireless transmission signal to terminal
51. Uplink radio information optical signal
52 ... Transmission signal to communication partner
53 ... Received signal from communication partner
54. Downlink radio information optical signal
55 ... Radio information digital signal
56: Oscillation frequency signal
57. Band-limited wireless information digital signal
60: Clock frequency signal
114 ... Digital signal processor (DSP)
115... DSP control software control unit
601 ... Receiver for wireless signal light transmission
602 ... Radio signal light transmission / reception device
603 ... Graph showing frequency spectrum distribution
604... Frequency fbl that divides the band into two
605 ... Simple base station
606 ... Antenna
607 ... Antenna duplexer
608 ... Electric-optical converter
609, 612 ... Optical amplifier
610: Optical coupler
613 ... Optical-electrical converter
614, 618 ... distributor
615,616,625,626 ... filter
617 ... Optical amplifier
619 ... Broadband wireless receiver
620 ... Narrow band radio receiver
621 ... Broadband wireless transmitter
622 ... Narrow band wireless transmitter
623, 624 ... Hybrid circuit
629, 631, 633 ... Optical amplifier
632 ... Optical coupler or optical filter
634 ... Optical-electrical converter (O / E)
699 ... Distributor
101, 1102, 1103, 1104 ... antenna
1105: Signal synthesizer
2101 ... high frequency analog part
2102 ... Analog-to-digital converter
2103: Digital-analog converter
2104: FPGA loaded with digital down-conversion software
2105: Digital signal processing (DSP) loaded with modem software, channel codec software, audio codec software, etc., compatible with the multi-access method
2106: Control MPU for loading control software for wireless transmission / reception
2107, 2108, 2109, 2110, 2111 ... clock source

Claims (7)

  1. A plurality of base stations that perform wireless communication with terminals in the wireless zone, a centralized base station that performs centralized control for these base stations, and a wireless information signal related to a wireless communication signal transmitted and received by the base station Means for transmitting via an optical fiber connecting between the base station and the centralized base station, and the centralized base station performs modulation / demodulation of the radio information signal by digital signal processing. In a radio communication base station apparatus comprising modulation / demodulation means that can change the modulation / demodulation function,
    The base station includes
    First frequency conversion means for converting the frequency of a wireless communication signal to be transmitted;
    Second frequency converting means for converting the frequency of the received wireless communication signal;
    A conversion band variable analog-digital conversion means for converting the radio communication signal frequency-converted by the second frequency conversion means into a digital signal for transmission to the centralized base station;
    A conversion band variable digital-analog conversion means for converting a wireless information signal modulated and transmitted from the centralized base station into an analog signal and supplying the analog signal to the first frequency conversion means;
    Generates a frequency conversion amount of the first and second frequency conversion means and a signal for controlling a conversion band of the analog-digital conversion means and the digital-analog conversion means from a variable control signal sent from the central base station And means for
    The central base station includes
    Control means for generating, as a control signal, a frequency conversion amount of the frequency conversion means on the base station side and a signal for variably controlling the conversion band of the analog-digital conversion means and the digital-analog conversion means;
    A radio communication base station apparatus comprising means for adding a control signal generated by the control means to a radio information signal.
  2. A plurality of base stations that perform wireless communication with terminals in the wireless zone, a centralized base station that performs centralized control for these base stations, and a wireless information signal related to a wireless communication signal transmitted and received by the base station Means for transmitting via an optical fiber connecting between the base station and the centralized base station, and the centralized base station performs modulation / demodulation of a radio information signal by digital signal processing; In a radio communication base station apparatus comprising modulation / demodulation means that can change the modulation / demodulation function by
    The base station includes
    Extracting means for extracting a clock signal and a frequency signal for frequency conversion from a signal sent from the centralized base station;
    First frequency converting means for converting the frequency of the radio communication signal to be transmitted by using the frequency signal extracted and given by the extracting means for up-conversion;
    Second frequency conversion means for converting the frequency of the received wireless communication signal to down-convert using the frequency signal extracted and given by the extraction means;
    A conversion band for operating the radio communication signal frequency-converted by the second frequency conversion means to be converted into a digital signal by operating in response to the clock signal extracted and given by the extraction means for transmission to the centralized base station Variable analog-to-digital conversion means;
    A conversion band to be applied to the first frequency conversion means by converting the radio information signal modulated and transmitted from the central base station into an analog signal by operating in response to the clock signal extracted and given by the extraction means Variable digital-analog conversion means,
    The central base station includes first variable frequency oscillation means of an oscillation frequency variable type that generates a frequency signal used for frequency conversion of a radio communication signal;
    A variable second variable frequency oscillation means for generating a clock signal for driving the analog-digital conversion means and the digital-analog conversion means in the base station;
    An oscillation frequency variable means for variably controlling the oscillation frequency of the first and second variable frequency oscillation means.
  3. A plurality of base stations that perform wireless communication with terminals in the wireless zone, a centralized base station that performs centralized control for these base stations, and a wireless information signal related to a wireless communication signal transmitted and received by the base station In a radio communication base station apparatus comprising means for transmitting via an optical fiber connecting between the base station and the centralized base station, the centralized base station comprising modem means for performing modulation / demodulation of a radio information signal by digital signal processing ,
    The centralized base station is
    Means for transmitting a radio information digital signal, a clock frequency signal Sc, and a frequency conversion signal Sm (however, a frequency component of Sc ≦ a frequency component of Sm) to the base station;
    The base station includes
    Means for obtaining a radio information digital signal, a clock frequency signal Sc and a frequency conversion signal Sm from the signal transmitted from the central base station;
    First frequency conversion means for up-converting a wireless communication signal to be transmitted using the frequency conversion signal Sm;
    A second frequency conversion means for down-converting the received wireless communication signal using the frequency conversion signal Sm;
    An analog-to-digital conversion means with variable conversion band for operating the radio communication signal frequency-converted by the second frequency conversion means to be converted into a digital signal by operating in correspondence with the clock frequency signal Sc for transmission to the centralized base station. When,
    A digital information / analog conversion means having a variable conversion band for converting the radio information signal modulated from the centralized base station into an analog signal by operating in correspondence with the clock frequency signal Sc and giving it to the first frequency conversion means. And
    The conversion frequency band of the analog-digital conversion means and the digital-analog conversion means is varied using the clock frequency signal Sc, and the frequency conversion of the radio communication signal is performed using the frequency conversion signal Sm. Wireless communication base station device.
  4. In the radio communication base station apparatus according to claim 1,
    The centralized base station is
    Means for transmitting a wireless information digital signal to the base station ;
    The base station
    Means for varying the conversion band of the analog-digital conversion means and the digital-analog conversion means according to a clock frequency;
    And means for recovering a clock frequency fc from the transmitted radio information digital signals,
    A radio communication base station apparatus characterized in that the regenerated clock frequency fc is used as a clock signal for operation of the analog-digital conversion means and the digital-analog conversion means.
  5. In the radio communication base station apparatus according to claim 4,
    The centralized base station is
    Means for transmitting a wireless information digital signal and a frequency conversion signal Sm to the base station ;
    The base station
    Means for extracting a frequency conversion signal Sm from the signal transmitted from the central base station;
    A radio communication base station apparatus comprising means for performing frequency conversion of a radio communication signal using the frequency conversion signal Sm.
  6. The radio communication base station apparatus according to any one of claims 3 to 5,
    Wherein the radio information digital signals for transmission to the base station from the centralized base station, a radio communication base station apparatus characterized by the addition of band limitation for blocking harmonics.
  7. Provided with a plurality of simplified base stations that perform wireless communication with terminals in the wireless zone, a centralized base station that performs centralized control for these simplified base stations, and a wireless communication signal that is transmitted and received by the simplified base station A means for transmitting information signals via an optical fiber connecting a simple base station and a centralized base station is provided. The centralized base station performs modulation / demodulation of radio information signals by digital signal processing, and changes the band. In a wireless communication base station apparatus equipped with modulation / demodulation means capable of changing the modulation / demodulation function by software,
    The central base station includes
    A digital-analog conversion means for converting an output digital signal of the modulation / demodulation means into a first wireless information analog signal;
    Means for transmitting a frequency signal Sm for frequency conversion between the first radio information analog signal and the radio communication signal to the simplified base station side;
    Means for receiving a second radio information analog signal transmitted from the simple base station;
    An analog-to-digital conversion means for converting the second wireless information analog signal into an input digital signal of the modulation / demodulation means,
    In the simple base station,
    Extracting means for extracting the first radio information analog signal and the frequency signal Sm transmitted from the centralized base station;
    Means for converting the frequency of the first wireless information signal using the frequency signal Sm extracted by the extracting means and obtaining a wireless communication signal to be transmitted to the terminal;
    Means for receiving a wireless communication signal from the terminal and performing frequency conversion using the frequency signal Sm extracted by the extracting means to obtain a second wireless information analog signal;
    Means for transmitting the obtained second wireless information analog signal to the centralized base station, and a wireless communication base station apparatus.
JP31626498A 1998-11-06 1998-11-06 Wireless communication base station equipment Expired - Fee Related JP4095185B2 (en)

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