JPH11186966A - Optical radio transmission system - Google Patents
Optical radio transmission systemInfo
- Publication number
- JPH11186966A JPH11186966A JP9349071A JP34907197A JPH11186966A JP H11186966 A JPH11186966 A JP H11186966A JP 9349071 A JP9349071 A JP 9349071A JP 34907197 A JP34907197 A JP 34907197A JP H11186966 A JPH11186966 A JP H11186966A
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- amplifier
- radio
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、光空間伝送方式に
より、周波数の異なる複数の無線信号を伝送する光無線
伝送システムに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical wireless transmission system for transmitting a plurality of wireless signals having different frequencies in an optical space transmission system.
【０００２】[0002]
【従来の技術】図４は、従来の無線伝送システムの構成
例を示す。図において、無線送受信機３の入力１〜入力
Ｎの電気信号は、変調器１１−１〜１１−Ｎで無線信号
に変換されて周波数変換器１２−１〜１２−Ｎに入力さ
れる。各無線信号は、周波数変換器１２−１〜１２−Ｎ
で周波数間隔が等間隔になるようにそれぞれ周波数変換
され、合波器１３で合波される。合波器１３から出力さ
れる周波数多重信号は、アッテネータ３１を介して増幅
器１４−１に入力される。アッテネータ３１は、周波数
多重信号の入力レベルを調整し、増幅器１４−１におけ
る相互変調歪の影響が小さくなるようなレベルに設定す
る。増幅器１４−１で増幅された周波数多重信号は、帯
域通過フィルタ３２で帯域外成分が濾波され、送受分離
器３３を介してアンテナ３４から送信される。2. Description of the Related Art FIG. 4 shows a configuration example of a conventional radio transmission system. In the figure, electric signals of input 1 to input N of the radio transceiver 3 are converted into radio signals by modulators 11-1 to 11-N and input to frequency converters 12-1 to 12-N. Each radio signal is transmitted to each of frequency converters 12-1 to 12-N.
Are frequency-converted so that the frequency intervals become equal, and are multiplexed by the multiplexer 13. The frequency multiplexed signal output from the multiplexer 13 is input to the amplifier 14-1 via the attenuator 31. The attenuator 31 adjusts the input level of the frequency multiplexed signal and sets the level so that the influence of the intermodulation distortion in the amplifier 14-1 is reduced. The frequency-division multiplexed signal amplified by the amplifier 14-1 is filtered out of band components by the band-pass filter 32, and transmitted from the antenna 34 via the transmission / reception separator 33.
【０００３】無線送受信機４のアンテナ４４に受信され
た周波数多重信号は、送受分離器４３を介して増幅器２
４−２に入力される。増幅器２４−２で増幅された周波
数多重信号は、分波器２７で各周波数の無線信号に分波
され、復調器２８−１〜２８−Ｎでそれぞれ電気信号に
復調して出力１〜出力Ｎとなる。[0003] The frequency multiplexed signal received by the antenna 44 of the radio transceiver 4 is transmitted through the transmission / reception separator 43 to the amplifier 2.
4-2. The frequency multiplexed signal amplified by the amplifier 24-2 is demultiplexed into radio signals of each frequency by the demultiplexer 27, demodulated into electric signals by demodulators 28-1 to 28-N, and output 1 to output N Becomes
【０００４】同様に、無線送受信機４の入力１′〜入力
Ｎ′の電気信号は、変調器２１−１〜２１−Ｎで無線信
号に変換されて周波数変換器２２−１〜２２−Ｎに入力
される。各無線信号は、周波数変換器２２−１〜２２−
Ｎで周波数間隔が等間隔になるようにそれぞれ周波数変
換され、合波器２３で合波される。合波器２３から出力
される周波数多重信号は、アッテネータ４１を介して増
幅器２４−１に入力される。アッテネータ４１は、周波
数多重信号の入力レベルを調整し、増幅器２４−１にお
ける相互変調歪の影響が小さくなるようなレベルに設定
する。増幅器２４−１で増幅された周波数多重信号は、
帯域通過フィルタ４２で帯域外成分が濾波され、送受分
離器４３を介してアンテナ４４から送信される。Similarly, the electric signals at the inputs 1 'to N' of the radio transceiver 4 are converted into radio signals by the modulators 21-1 to 21-N and transmitted to the frequency converters 22-1 to 22-N. Is entered. Each radio signal is transmitted to the frequency converters 22-1 to 22-.
The frequency is converted so that the frequency intervals become equal at N, and are multiplexed by the multiplexer 23. The frequency multiplexed signal output from the multiplexer 23 is input to the amplifier 24-1 via the attenuator 41. The attenuator 41 adjusts the input level of the frequency-division multiplexed signal and sets the level so that the influence of the intermodulation distortion in the amplifier 24-1 is reduced. The frequency multiplexed signal amplified by the amplifier 24-1 is
The out-of-band component is filtered by the band-pass filter 42 and transmitted from the antenna 44 via the transmission / reception separator 43.
【０００５】無線送受信機３のアンテナ３４に受信され
た周波数多重信号は、送受分離器３３を介して増幅器１
４−２に入力される。増幅器１４−２で増幅された周波
数多重信号は、分波器１７で各周波数の無線信号に分波
され、復調器１８−１〜１８−Ｎでそれぞれ電気信号に
復調して出力１′〜出力Ｎ′となる。[0005] The frequency multiplexed signal received by the antenna 34 of the radio transceiver 3 is transmitted to the amplifier 1 through the transmission / reception separator 33.
4-2. The frequency multiplexed signal amplified by the amplifier 14-2 is demultiplexed into radio signals of each frequency by the demultiplexer 17, demodulated into electric signals by the demodulators 18-1 to 18-N, and output 1 'to output N '.
【０００６】[0006]
【発明が解決しようとする課題】ところで、無線送受信
機３，４に用いられている増幅器等の非線形素子に周波
数多重信号を過入力した場合には、相互変調歪により希
望帯域内外に不要波が生じる。そのため、制限帯域外の
不要波を帯域通過フィルタ３２，４２を用いて濾波する
必要が生じる。また、不要波と希望波が同一の周波数に
なると、希望波の伝送品質が著しく劣化するので、増幅
器等への入力レベルが過入力とならないように制限する
必要が生じる。When a frequency multiplexed signal is excessively input to a non-linear element such as an amplifier used in the radio transceivers 3 and 4, unnecessary waves are generated inside and outside a desired band due to intermodulation distortion. Occurs. Therefore, it becomes necessary to filter unnecessary waves outside the restricted band using the band-pass filters 32 and 42. Further, when the unnecessary wave and the desired wave have the same frequency, the transmission quality of the desired wave is significantly deteriorated. Therefore, it is necessary to limit the input level to the amplifier or the like so as not to be excessive.
【０００７】本発明は、このような制限を緩和し、周波
数の異なる複数の無線信号を高品質で伝送することがで
きる光無線伝送システムを提供することを目的とする。An object of the present invention is to provide an optical wireless transmission system capable of alleviating such restrictions and transmitting a plurality of wireless signals having different frequencies with high quality.
【０００８】[0008]
【課題を解決するための手段】本発明は、送信側で複数
の電気信号を光信号に変換し、光信号を空間伝送し、受
信側で光信号を複数の電気信号に再変換する光無線伝送
システムにおいて、送信側の周波数変換手段で複数の電
気信号を互いに異なる周波数の電気信号に変換し、周波
数変換された複数の電気信号を合波手段で合波し、この
周波数多重信号を増幅手段で増幅し、増幅された周波数
多重信号を電気／光変換手段で光強度変調信号に変換し
て空間に出力する。SUMMARY OF THE INVENTION The present invention is directed to an optical radio for converting a plurality of electrical signals into optical signals on a transmitting side, spatially transmitting the optical signals, and reconverting the optical signals into a plurality of electrical signals on a receiving side. In a transmission system, a plurality of electric signals are converted into electric signals of different frequencies by a frequency conversion unit on a transmission side, and the plurality of electric signals subjected to frequency conversion are multiplexed by a multiplexing unit. Then, the amplified frequency multiplexed signal is converted into a light intensity modulation signal by an electric / optical conversion means and output to space.
【０００９】このように、増幅された周波数多重信号を
光強度変調信号に変換して光空間伝送する構成であるの
で、帯域制限が大幅に緩和され、増幅手段の出力に含ま
れる希望帯域外の不要波を帯域通過フィルタを用いて濾
波する必要がない。As described above, since the amplified frequency multiplexed signal is converted into an optical intensity modulated signal and transmitted in the optical space, the band limitation is greatly relaxed, and the frequency band outside the desired band included in the output of the amplifying means is reduced. It is not necessary to filter unnecessary waves using a band-pass filter.
【００１０】また、周波数変換手段で複数の電気信号を
互いに異なる周波数の電気信号に変換する際に、各電気
信号の周波数を相互変調歪の影響が最小限になる周波数
に設定する周波数制御手段を備える。すなわち、不要波
と希望波が同一の周波数にならないように設定すること
により、増幅器等の非線形素子への入力制限を緩和する
ことができる。When converting a plurality of electric signals into electric signals having mutually different frequencies by the frequency converting means, a frequency control means for setting the frequency of each electric signal to a frequency at which the influence of intermodulation distortion is minimized. Prepare. In other words, by setting the unwanted wave and the desired wave so as not to have the same frequency, it is possible to ease the input limitation to a nonlinear element such as an amplifier.
【００１１】[0011]
【発明の実施の形態】（第１の実施形態）図１は、本発
明の光無線伝送システムの第１の実施形態を示す。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows a first embodiment of the optical wireless transmission system of the present invention.
【００１２】図において、光無線送受信機１の入力１〜
入力Ｎの電気信号は、変調器１１−１〜１１−Ｎで無線
信号に変換されて周波数変換器１２−１〜１２−Ｎに入
力される。各無線信号は、周波数変換器１２−１〜１２
−Ｎで周波数間隔が等間隔になるようにそれぞれ周波数
変換され、合波器１３で合波されて増幅器１４−１に入
力される。増幅器１４−１で増幅された周波数多重信号
は電気／光変換器１５に入力され、光強度変調信号に変
換されて空間に出力される。なお、電気／光変換器１５
には、光強度変調信号を光ビームとして空間に出力する
ための手段が含まれる。In FIG. 1, inputs 1 to 1 of an optical wireless transceiver 1 are shown.
The electric signals at the input N are converted into radio signals by the modulators 11-1 to 11-N and input to the frequency converters 12-1 to 12-N. Each wireless signal is transmitted to each of frequency converters 12-1 to 12-12.
The frequency is converted so that the frequency interval becomes equal at -N, and the frequency is converted by the multiplexer 13 and input to the amplifier 14-1. The frequency multiplexed signal amplified by the amplifier 14-1 is input to the electrical / optical converter 15, converted into an optical intensity modulated signal, and output to space. The electric / optical converter 15
Includes means for outputting a light intensity modulated signal to a space as a light beam.
【００１３】ここで、光領域では帯域制限がないので、
増幅後の周波数多重信号を帯域通過フィルタ等で濾波す
る必要がない。また、増幅器１４−１が過入力状態でも
動作可能であるので、増幅器１４−１の入力ダイナミッ
クレンジを拡大することができる。Here, since there is no band limitation in the optical region,
There is no need to filter the amplified frequency multiplexed signal with a band-pass filter or the like. Further, since the amplifier 14-1 can operate even in an over-input state, the input dynamic range of the amplifier 14-1 can be expanded.
【００１４】光無線送受信機２では、光無線送受信機１
から出射された光強度変調信号を光／電気変換器２６に
集光して受光し、周波数多重信号に変換して増幅器２４
−２に入力する。増幅器２４−２で増幅された周波数多
重信号は、分波器２７で各周波数の無線信号に分波さ
れ、復調器２８−１〜２８−Ｎでそれぞれ電気信号に復
調して出力１〜出力Ｎとなる。In the optical wireless transceiver 2, the optical wireless transceiver 1
The light intensity modulated signal emitted from the optical modulator is condensed and received by the optical / electrical converter 26, converted into a frequency multiplexed signal, and
Input to -2. The frequency multiplexed signal amplified by the amplifier 24-2 is demultiplexed into radio signals of each frequency by the demultiplexer 27, demodulated into electric signals by demodulators 28-1 to 28-N, and output 1 to output N Becomes
【００１５】同様に、光無線送受信機２の入力１′〜入
力Ｎ′の電気信号は、変調器２１−１〜２１−Ｎで無線
信号に変換されて周波数変換器２２−１〜２２−Ｎに入
力される。各無線信号は、周波数変換器２２−１〜２２
−Ｎで周波数間隔が等間隔になるようにそれぞれ周波数
変換され、合波器２３で合波されて増幅器２４−１に入
力される。増幅器２４−１で増幅された周波数多重信号
は電気／光変換器２５に入力され、光強度変調信号に変
換されて空間に出力される。なお、電気／光変換器２５
には、光強度変調信号を光ビームとして空間に出力する
ための手段が含まれる。Similarly, the electric signals at the inputs 1 'to N' of the optical radio transceiver 2 are converted into radio signals by the modulators 21-1 to 21-N, and are converted into frequency signals 22-1 to 22-N. Is input to Each radio signal is transmitted to each of the frequency converters 22-1 to 22-2.
The frequency is converted so that the frequency interval becomes equal at -N, and the signals are multiplexed by the multiplexer 23 and input to the amplifier 24-1. The frequency multiplexed signal amplified by the amplifier 24-1 is input to the electric / optical converter 25, converted into a light intensity modulation signal, and output to space. The electric / optical converter 25
Includes means for outputting a light intensity modulated signal to a space as a light beam.
【００１６】光無線送受信機１では、光無線送受信機２
から出射された光強度変調信号を光／電気変換器１６に
集光して受光し、周波数多重信号に変換して増幅器１４
−２に入力する。増幅器１４−２で増幅された周波数多
重信号は、分波器１７で各周波数の無線信号に分波さ
れ、復調器１８−１〜１８−Ｎでそれぞれ電気信号に復
調して出力１′〜出力Ｎ′となる。In the optical wireless transceiver 1, the optical wireless transceiver 2
The light intensity modulated signal emitted from the multiplexor is condensed and received by the optical / electrical converter 16, converted into a frequency multiplexed signal, and
Input to -2. The frequency multiplexed signal amplified by the amplifier 14-2 is demultiplexed into radio signals of each frequency by the demultiplexer 17, demodulated into electric signals by the demodulators 18-1 to 18-N, and output 1 'to output N '.
【００１７】図２は、複数の無線信号の周波数配置と相
互変調歪の関係を示す。図２(a) に示すように、複数の
無線信号の周波数配置Ｆ１，Ｆ２，Ｆ３，Ｆ４を等間隔
にすると、例えば３次の相互変調歪成分２Ｆ１−Ｆ２，
Ｆ１＋Ｆ２−Ｆ３等が周波数Ｆ３，Ｆ４と同一周波数に
なることがある。この場合には、周波数Ｆ３，Ｆ４の無
線信号の伝送品質が劣化する。FIG. 2 shows the relationship between the frequency allocation of a plurality of radio signals and intermodulation distortion. As shown in FIG. 2A, when the frequency arrangements F1, F2, F3, and F4 of a plurality of radio signals are set at equal intervals, for example, a third-order intermodulation distortion component 2F1-F2
F1 + F2-F3 may be the same as the frequencies F3 and F4. In this case, the transmission quality of the radio signals of the frequencies F3 and F4 deteriorates.
【００１８】一方、図２(b) に示すように、複数の無線
信号の周波数配置Ｆ１，Ｆ２，Ｆ３，Ｆ４を相互変調歪
の影響がないように配置する。例えば、３次の相互変調
歪成分２Ｆ１−Ｆ２，Ｆ１＋Ｆ２−Ｆ３等が周波数Ｆ
３，Ｆ４と同一周波数にならないように設定すると、周
波数Ｆ３，Ｆ４の無線信号の伝送品質の劣化は回避でき
る。On the other hand, as shown in FIG. 2B, the frequency arrangements F1, F2, F3, F4 of a plurality of radio signals are arranged so as not to be affected by intermodulation distortion. For example, the third-order intermodulation distortion components 2F1-F2, F1 + F2-F3, etc.
If the frequency is not set to the same as that of the radio signals F3 and F4, the deterioration of the transmission quality of the radio signals of the frequencies F3 and F4 can be avoided.
【００１９】（第２の実施形態）図３は、本発明の光無
線伝送システムの第２の実施形態を示す。図において、
光無線送受信機１の入力１〜入力Ｎの電気信号は、変調
器１１−１〜１１−Ｎで無線信号に変換されて周波数変
換器１２−１〜１２−Ｎに入力される。周波数変換器１
２−１〜１２−Ｎは、周波数制御回路１９からの制御信
号により、各無線信号の周波数を図２(b) に示すような
相互変調歪の影響が最小限になるように周波数変換す
る。このように周波数変換された各無線信号は、合波器
１３で合波されて増幅器１４−１に入力される。増幅器
１４−１で増幅された周波数多重信号は電気／光変換器
１５に入力され、光強度変調信号に変換されて空間に出
力される。なお、電気／光変換器１５には、光強度変調
信号を光ビームとして空間に出力するための手段が含ま
れる。(Second Embodiment) FIG. 3 shows a second embodiment of the optical wireless transmission system of the present invention. In the figure,
The electrical signals at the inputs 1 to N of the optical wireless transceiver 1 are converted into wireless signals by the modulators 11-1 to 11-N and input to the frequency converters 12-1 to 12-N. Frequency converter 1
2-1 to 12-N convert the frequency of each radio signal by the control signal from the frequency control circuit 19 so that the influence of the intermodulation distortion as shown in FIG. Each frequency-converted radio signal is multiplexed by the multiplexer 13 and input to the amplifier 14-1. The frequency multiplexed signal amplified by the amplifier 14-1 is input to the electrical / optical converter 15, converted into an optical intensity modulated signal, and output to space. The electric / optical converter 15 includes a unit for outputting a light intensity modulation signal to a space as a light beam.
【００２０】本実施形態では、増幅器１４−１や電気／
光変換器１５などの非線形素子を用いても、相互変調歪
の影響が最小限に抑えられるので、各無線信号の伝送品
質の劣化は小さい。また、光領域では帯域制限がないの
で、増幅後の周波数多重信号を帯域通過フィルタ等で濾
波する必要がなく、増幅器１４−１が過入力状態でも動
作可能であるので、増幅器１４−１の入力ダイナミック
レンジを拡大することができる。In this embodiment, the amplifier 14-1 and the electric / electrical
Even if a non-linear element such as the optical converter 15 is used, the influence of the intermodulation distortion is minimized, so that the deterioration of the transmission quality of each radio signal is small. Further, since there is no band limitation in the optical domain, there is no need to filter the amplified frequency multiplexed signal with a band-pass filter or the like, and the amplifier 14-1 can operate even in an over-input state. The dynamic range can be expanded.
【００２１】光無線送受信機２では、光無線送受信機１
から出射された光強度変調信号を光／電気変換器２６に
集光して受光し、周波数多重信号に変換して増幅器２４
−２に入力する。増幅器２４−２で増幅された周波数多
重信号は、分波器２７で各周波数の無線信号に分波さ
れ、復調器２８−１〜２８−Ｎでそれぞれ電気信号に復
調して出力１〜出力Ｎとなる。In the optical wireless transceiver 2, the optical wireless transceiver 1
The light intensity modulated signal emitted from the optical modulator is condensed and received by the optical / electrical converter 26, converted into a frequency multiplexed signal, and
Input to -2. The frequency multiplexed signal amplified by the amplifier 24-2 is demultiplexed into radio signals of each frequency by the demultiplexer 27, demodulated into electric signals by demodulators 28-1 to 28-N, and output 1 to output N Becomes
【００２２】同様に、光無線送受信機２の入力１′〜入
力Ｎ′の電気信号は、変調器２１−１〜２１−Ｎで無線
信号に変換されて周波数変換器２２−１〜２２−Ｎに入
力される。周波数変換器２２−１〜２２−Ｎは、周波数
制御回路２９からの制御信号により、各無線信号の周波
数を図２(b) に示すような相互変調歪の影響が最小限に
なるように周波数変換する。このように周波数変換され
た各無線信号は、合波器２３で合波されて増幅器２４−
１に入力される。増幅器２４−１で増幅された周波数多
重信号は電気／光変換器２５に入力され、光強度変調信
号に変換されて空間に出力される。なお、電気／光変換
器２５には、光強度変調信号を光ビームとして空間に出
力するための手段が含まれる。Similarly, the electric signals at the inputs 1 'to N' of the optical radio transceiver 2 are converted into radio signals by the modulators 21-1 to 21-N, and are converted into frequency signals 22-1 to 22-N. Is input to The frequency converters 22-1 to 22-N adjust the frequency of each radio signal in accordance with a control signal from the frequency control circuit 29 so that the influence of intermodulation distortion as shown in FIG. Convert. Each of the radio signals thus frequency-converted is multiplexed by the multiplexer 23 and is amplified by the amplifier 24-
1 is input. The frequency multiplexed signal amplified by the amplifier 24-1 is input to the electric / optical converter 25, converted into a light intensity modulation signal, and output to space. The electric / optical converter 25 includes a unit for outputting a light intensity modulated signal to a space as a light beam.
【００２３】光無線送受信機１では、光無線送受信機２
から出射された光強度変調信号を光／電気変換器１６に
集光して受光し、周波数多重信号に変換して増幅器１４
−２に入力する。増幅器１４−２で増幅された周波数多
重信号は、分波器１７で各周波数の無線信号に分波さ
れ、復調器１８−１〜１８−Ｎでそれぞれ電気信号に復
調して出力１′〜出力Ｎ′となる。In the optical wireless transceiver 1, the optical wireless transceiver 2
The light intensity modulated signal emitted from the multiplexor is condensed and received by the optical / electrical converter 16, converted into a frequency multiplexed signal, and
Input to -2. The frequency multiplexed signal amplified by the amplifier 14-2 is demultiplexed into radio signals of each frequency by the demultiplexer 17, demodulated into electric signals by the demodulators 18-1 to 18-N, and output 1 'to output N '.
【００２４】[0024]
【発明の効果】以上説明したように、本発明の光無線伝
送システムは、増幅された周波数多重信号を光強度変調
信号に変換して光空間伝送する構成であるので、帯域制
限を大幅に緩和することができる。これにより、増幅手
段の出力に含まれる希望帯域外の不要波を濾波するため
の帯域通過フィルタを省くことができる。As described above, the optical wireless transmission system of the present invention converts the amplified frequency-division multiplexed signal into an optical intensity modulation signal and transmits it in the optical space, so that the band limitation is greatly eased. can do. As a result, a band-pass filter for filtering unnecessary waves outside the desired band included in the output of the amplifying means can be omitted.
【００２５】また、周波数の異なる複数の電気信号を相
互変調歪の影響が最小限になる周波数に変換して多重す
ることにより、不要波と希望波が同一の周波数にならな
いように設定することができる。これにより、増幅器等
の非線形素子への入力制限を緩和することができるとと
もに、相互変調歪による伝送品質の劣化を回避すること
ができる。Further, by converting a plurality of electric signals having different frequencies to a frequency at which the influence of the intermodulation distortion is minimized and multiplexing, it is possible to set the unnecessary wave and the desired wave so as not to have the same frequency. it can. As a result, it is possible to alleviate the input limitation to the non-linear element such as the amplifier and to avoid the deterioration of the transmission quality due to the intermodulation distortion.
【図１】本発明の光無線伝送システムの第１の実施形態
を示すブロック図。FIG. 1 is a block diagram showing a first embodiment of an optical wireless transmission system according to the present invention.
【図２】複数の無線信号の周波数配置と相互変調歪の関
係を示す図。FIG. 2 is a diagram illustrating a relationship between frequency allocation of a plurality of radio signals and intermodulation distortion.
【図３】本発明の光無線伝送システムの第２の実施形態
を示すブロック図。FIG. 3 is a block diagram showing a second embodiment of the optical wireless transmission system of the present invention.
【図４】従来の無線伝送システムの構成例を示すブロッ
ク図。FIG. 4 is a block diagram showing a configuration example of a conventional wireless transmission system.
１，２ 光無線送受信機 ３，４ 無線送受信機 １１，２１ 変調器 １２，２２ 周波数変換器 １３，２３ 合波器 １４，２４ 増幅器 １５，２５ 電気／光変換器 １６，２６ 光／電気変換器 １７，２７ 分波器 １８，２８ 復調器 １９，２９ 周波数制御回路 ３１ アッテネータ ３２ 帯域通過フィルタ ３３ 送受分離器 ３４ アンテナ 1,2 optical wireless transceiver 3,4 wireless transceiver 11,21 modulator 12,22 frequency converter 13,23 multiplexer 14,24 amplifier 15,25 electric / optical converter 16,26 optical / electric converter 17, 27 Demultiplexer 18, 28 Demodulator 19, 29 Frequency control circuit 31 Attenuator 32 Bandpass filter 33 Transmit / receive separator 34 Antenna
Claims (2)
し、前記光信号を空間伝送し、受信側で前記光信号を前
記複数の電気信号に再変換する光無線伝送システムにお
いて、 前記複数の電気信号を互いに異なる周波数の電気信号に
変換する周波数変換手段と、 前記周波数変換された複数の電気信号を合波して周波数
多重信号として出力する合波手段と、 前記周波数多重信号を増幅する増幅手段と、 前記増幅された周波数多重信号を光強度変調信号に変換
して空間に出力する電気／光変換手段とを備えたことを
特徴とする光無線伝送システム。1. An optical wireless transmission system that converts a plurality of electrical signals into optical signals on a transmitting side, spatially transmits the optical signals, and reconverts the optical signals into the plurality of electrical signals on a receiving side. Frequency conversion means for converting a plurality of electric signals into electric signals having different frequencies, multiplexing means for multiplexing the frequency-converted electric signals and outputting the multiplexed electric signals as a frequency multiplexed signal, and amplifying the frequency multiplexed signal An optical-to-optical transmission system, comprising: an amplifying unit that converts the amplified frequency multiplexed signal into an optical intensity modulated signal and outputs the signal to a space.
おいて、 複数の電気信号を互いに異なる周波数の電気信号に変換
する際に、各電気信号の周波数を相互変調歪の影響が最
小限になる周波数に設定する周波数制御手段を備えたこ
とを特徴とする光無線伝送システム。2. The optical wireless transmission system according to claim 1, wherein when converting the plurality of electric signals into electric signals having different frequencies from each other, the influence of the intermodulation distortion on the frequency of each electric signal is minimized. An optical wireless transmission system comprising frequency control means for setting a frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9349071A JPH11186966A (en) | 1997-12-18 | 1997-12-18 | Optical radio transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9349071A JPH11186966A (en) | 1997-12-18 | 1997-12-18 | Optical radio transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11186966A true JPH11186966A (en) | 1999-07-09 |
Family
ID=18401301
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9349071A Pending JPH11186966A (en) | 1997-12-18 | 1997-12-18 | Optical radio transmission system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11186966A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007096928A (en) * | 2005-09-29 | 2007-04-12 | Oki Electric Ind Co Ltd | Frequency signal synthesis and separation circuit, and optical wireless merge transmission system, optical modulation module and optical communication system using the circuit |
| JP2011228869A (en) * | 2010-04-19 | 2011-11-10 | Hokuyo Automatic Co | Light data demodulator, light data modulator, and light data transmission device |
-
1997
- 1997-12-18 JP JP9349071A patent/JPH11186966A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007096928A (en) * | 2005-09-29 | 2007-04-12 | Oki Electric Ind Co Ltd | Frequency signal synthesis and separation circuit, and optical wireless merge transmission system, optical modulation module and optical communication system using the circuit |
| JP2011228869A (en) * | 2010-04-19 | 2011-11-10 | Hokuyo Automatic Co | Light data demodulator, light data modulator, and light data transmission device |
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