JP4102272B2 - Optical transmitter for optical-wireless communication system - Google Patents

Optical transmitter for optical-wireless communication system Download PDF

Info

Publication number
JP4102272B2
JP4102272B2 JP2003301795A JP2003301795A JP4102272B2 JP 4102272 B2 JP4102272 B2 JP 4102272B2 JP 2003301795 A JP2003301795 A JP 2003301795A JP 2003301795 A JP2003301795 A JP 2003301795A JP 4102272 B2 JP4102272 B2 JP 4102272B2
Authority
JP
Japan
Prior art keywords
optical
signal
frequency
electric
carrier
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2003301795A
Other languages
Japanese (ja)
Other versions
JP2005073066A (en
Inventor
友宏 谷口
尚也 桜井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Original Assignee
Nippon Telegraph and Telephone Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Telegraph and Telephone Corp filed Critical Nippon Telegraph and Telephone Corp
Priority to JP2003301795A priority Critical patent/JP4102272B2/en
Publication of JP2005073066A publication Critical patent/JP2005073066A/en
Application granted granted Critical
Publication of JP4102272B2 publication Critical patent/JP4102272B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
  • Lasers (AREA)
  • Optical Communication System (AREA)

Description

本発明は、広帯域信号光を利用した光−無線融合通信システムにおける光送信器、特に無線基地局に所望の無線信号を光信号で送信する光送信器に関する。   The present invention relates to an optical transmitter in an optical-radio fusion communication system using broadband signal light, and more particularly to an optical transmitter that transmits a desired radio signal to a radio base station as an optical signal.

図１、図２、図３はそれぞれ従来の光−無線融合通信システムにおける光送信器、無線基地局、無線加入者端末の一例を示したものであり、図４は従来の光−無線融合通信システムにおける電気周波数及び光周波数のスペクトルの一例を示したものである。   1, 2, and 3 show examples of an optical transmitter, a radio base station, and a wireless subscriber terminal in a conventional optical-wireless communication system, and FIG. 4 shows a conventional optical-wireless communication. 2 shows an example of electrical frequency and optical frequency spectra in a system.

光送信器１０１により光信号（１ｅ）が光伝送路を経て無線基地局１０７へ伝送される。ここで、電気発振器１０６からの出力信号が無線信号の周波数の半値に等しい周波数の電気搬送波信号（１ｃ）となるようにし、単一スペクトル光源１０３の出力光（１ｂ）に対して第１の光変調器１０４で搬送波抑圧両側波帯光変調を施す。さらに、第２の光変調器により、第１の光変調器の出力光（１ｄ）に対して入力端子１０２に入力されたディジタル信号（１ａ）で光強度変調を施して送信する。   An optical signal (1e) is transmitted from the optical transmitter 101 to the radio base station 107 through an optical transmission line. Here, the output signal from the electric oscillator 106 becomes an electric carrier signal (1c) having a frequency equal to half the frequency of the radio signal, and the first light is output with respect to the output light (1b) of the single spectrum light source 103. Modulator 104 performs carrier wave suppression double-sideband optical modulation. Further, the second optical modulator modulates the light intensity of the output light (1d) of the first optical modulator with the digital signal (1a) input to the input terminal 102 and transmits it.

無線基地局１０７においては、このような光信号（１ｅ）を１つの受光素子１０８で同時に自乗検波することにより差周波数成分（１ｆ）が得られ、必要に応じて増幅した後にアンテナ１０９から電波として送出することで、ミリ波帯の電気信号を直接伝送せず、また無線基地局にミリ波帯の電気発振器を用意することなくミリ波帯無線信号を伝送することが可能となる。   In the radio base station 107, the difference frequency component (1f) is obtained by simultaneously square-detecting such an optical signal (1e) with one light receiving element 108, and is amplified as necessary, and then amplified as a radio wave from the antenna 109. By transmitting, it is possible to transmit a millimeter-wave band radio signal without directly transmitting a millimeter-wave band electrical signal and without preparing a millimeter-wave band electrical oscillator in the radio base station.

ここで、伝送する光信号（１ｅ）の電界Ｅoptは次の数式で表すことできる。 Here, the electric field E opt of the optical signal (1e) to be transmitted can be expressed by the following equation.

Ｅopt＝ａiｃｏｓ｛２π（ｆc＋ｆRF／２）ｔ＋φ（ｔ）｝
＋ａiｃｏｓ｛２π（ｆc−ｆRF／２）ｔ＋φ（ｔ）｝ ……（１）
但し、ここで、ａiは振幅変調成分、ｆｃは光周波数、ｆRFは無線信号周波数、φ（ｔ）は単一スペクトル光源の位相雑音を表すものとする。 E opt = a i cos {2π (f c + f RF / 2) t + φ (t)}
+ A i cos {2π (f c −f RF / 2) t + φ (t)} (1)
Here, a i is an amplitude modulation component, fc is an optical frequency, f RF is a radio signal frequency, and φ (t) is a phase noise of a single spectrum light source.

この光信号（１ｅ）を受光素子で自乗検波して得られる信号（１ｆ）の電界ＥRFは次の数式で表すことができる。 The electric field E RF of the signal (1f) obtained by square detection of the optical signal (1e) by the light receiving element can be expressed by the following equation.

ＥRF∝ａi 2ｃｏｓ（２πｆRFｔ） ……（２）
（２）式においては、（１）式の光信号電界において存在していた単一スペクトル光源の位相雑音成分が相殺されており、周波数安定性の高い無線信号が得られることとなる。 E RF ∝a i 2 cos (2πf RF t) (2)
In the equation (2), the phase noise component of the single spectrum light source existing in the optical signal electric field of the equation (1) is canceled out, and a radio signal with high frequency stability can be obtained.

前記無線基地局１０７から送出された電波（１ｆ）を受信する無線加入者端末１１０においては、アンテナ１１１で受信した無線信号（１ｆ）と電気発振器１１２から出力された無線信号の周波数より中間周波数信号の周波数の分だけ高い周波数を有する電気搬送波信号（１ｇ）とを乗算器１１３に入力し、乗算器１１３の出力をフィルタ１１４に通すことで、中間周波数信号（１ｉ）を得る（例えば、非特許文献１参照）。
Ｈ．Ｓｃｈｍａｃｋ ａｎｄ Ｒ．Ｈｅｉｄｅｍａｎｎ，“Ｈｙｂｒｉｄ ｆｉｂｒｅ−ｒａｄｉｏ ｆｉｅｌｄ ｅｘｐｒｉｍｅｎｔ ａｔ ６０ＧＨｚ”，ＥＣＯＣ’９６，ｐｐ４．５９−４．６２ In the radio subscriber terminal 110 that receives the radio wave (1f) transmitted from the radio base station 107, an intermediate frequency signal is obtained from the frequency of the radio signal (1f) received by the antenna 111 and the radio signal output from the electric oscillator 112. An electric carrier signal (1g) having a frequency higher than the frequency of the input signal is input to the multiplier 113, and the output of the multiplier 113 is passed through the filter 114 to obtain the intermediate frequency signal (1i) (for example, non-patent Reference 1).
H. Schmack and R.M. Heidemann, “Hybrid fibre-radio field experience at 60 GHz”, ECOC '96, pp 4.59-4.62.

図１、図２、図３及び図４に挙げた従来例の場合は、各無線加入者端末において、中間周波数信号を得るため、局部発振器として電気発振器を用意する必要がある。広帯域信号を伝送する場合は、広い信号帯域が確保できるミリ波帯を用いることが予想されるが、ミリ波帯の電気発振器は高価である他、発振器の出力信号の周波数安定度を向上させるために構成が複雑になる。   In the case of the conventional examples shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, it is necessary to prepare an electric oscillator as a local oscillator in each wireless subscriber terminal in order to obtain an intermediate frequency signal. When transmitting a wideband signal, it is expected to use a millimeter wave band that can secure a wide signal band. However, an electric oscillator in the millimeter wave band is expensive and to improve the frequency stability of the output signal of the oscillator. The configuration becomes complicated.

本発明は、このような背景に行われたものであって、無線加入者端末の構成を安価かつ簡易にできる光送信器を提供することを目的とする。   The present invention has been made in view of such a background, and an object of the present invention is to provide an optical transmitter that can simplify and simplify the configuration of a wireless subscriber terminal.

本発明では、前記目的を達成するため、請求項１では、無線基地局に所望の無線信号を光信号で送信する光送信器において、光周波数ｆｃの単一スペクトルの光信号を発生する単一スペクトル光源と、前記無線信号の周波数ｆ RF の半値に等しい周波数ｆ RF ／２を有する電気搬送波信号を発生する第１の電気発振器と、前記無線基地局から送出された電波を受信する無線端末における中間周波数信号の周波数ｆ IF の半値に等しい周波数ｆ IF ／２を有する電気搬送波信号を発生する第２の電気発振器と、前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ RF ／２及びｆｃ−ｆ RF ／２の光周波数を有する光信号を出力する第１の光変調器と、前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ RF ／２＋ｆ IF ／２、ｆｃ＋ｆ RF ／２−ｆ IF ／２、ｆｃ−ｆ RF ／２＋ｆ IF ／２及びｆｃ−ｆ RF ／２−ｆ IF ／２の光周波数を有する光信号を出力する第２の光変調器と、前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えたことを特徴とする光送信器をもって解決手段とする。 In order to achieve the above object, according to the present invention, in claim 1, in an optical transmitter for transmitting a desired radio signal to a radio base station as an optical signal, a single spectrum optical signal having an optical frequency fc is generated. In a wireless terminal that receives a spectrum light source, a first electric oscillator that generates an electric carrier signal having a frequency f RF / 2 equal to half the frequency f RF of the wireless signal, and a radio wave transmitted from the wireless base station A second electric oscillator for generating an electric carrier signal having a frequency f IF / 2 equal to a half value of the frequency f IF of the intermediate frequency signal, and a first electric oscillator for the optical signal output from the single spectrum light source; and facilities the double sideband suppressed carrier light modulated by more electrical carrier signal, a first optical modulator for outputting an optical signal having an optical frequency fc + f RF / 2 and fc-f RF / 2, the first of To the optical signal output from the optical modulator, and facilities the double sideband suppressed carrier light modulated by the electrical carrier wave signal from the second electric generator, fc + f RF / 2 + f IF / 2, fc + f RF / 2-f IF / 2, fc−f RF / 2 + f IF / 2 and fc−f RF / 2−f IF / 2 from the second optical modulator that outputs an optical signal having an optical frequency , and the second optical modulator An optical transmitter characterized in that it comprises a third optical modulator that performs optical intensity modulation on the output optical signal with the input electrical digital signal.

また、請求項２では、無線基地局に所望の無線信号を光信号で送信する光送信器において、光周波数ｆｃの単一スペクトルの光信号を発生する単一スペクトル光源と、前記無線基地局から送出された電波を受信する無線端末における中間周波数信号の周波数ｆ IF の半値に等しい周波数ｆ IF ／２を有する電気搬送波信号を発生する第１の電気発振器と、前記無線信号の周波数ｆ RF の半値に等しい周波数ｆ RF ／２を有する電気搬送波信号を発生する第２の電気発振器と、前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ IF ／２及びｆｃ−ｆ IF ／２の光周波数を有する光信号を出力する第１の光変調器と、前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ RF ／２＋ｆ IF ／２、ｆｃ＋ｆ RF ／２−ｆ IF ／２、ｆｃ−ｆ RF ／２＋ｆ IF ／２及びｆｃ−ｆ RF ／２−ｆ IF ／２の光周波数を有する光信号を出力する第２の光変調器と、前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えたことを特徴とする光送信器をもって解決手段とする。 According to a second aspect of the present invention, in an optical transmitter that transmits a desired radio signal to a radio base station as an optical signal, a single spectrum light source that generates a single spectrum optical signal having an optical frequency fc, and the radio base station A first electric oscillator that generates an electric carrier signal having a frequency f IF / 2 equal to a half value of the frequency f IF of the intermediate frequency signal in a wireless terminal that receives the transmitted radio wave; and a half value of the frequency f RF of the wireless signal A second electric oscillator that generates an electric carrier signal having a frequency f RF / 2 equal to the optical signal, and the optical signal output from the single spectrum light source is suppressed by the electric carrier signal from the first electric oscillator. and facilities the double-sideband optical modulator, fc + f IF / 2 and fc-f IF / 2 of a first optical modulator for outputting an optical signal having an optical frequency, the light output from the first optical modulator Signal Against, and facilities the double sideband suppressed carrier light modulated by the electrical carrier wave signal from the second electric generator, fc + f RF / 2 + f IF / 2, fc + f RF / 2-f IF / 2, fc-f RF / 2 + f IF / 2 and fc−f RF / 2−f IF / 2 The second optical modulator that outputs an optical signal having an optical frequency, and the optical signal output from the second optical modulator are input. An optical transmitter comprising a third optical modulator that performs optical intensity modulation with an electrical digital signal is used as a solution.

請求項１あるいは２の発明によれば、光送信器から４つの光信号を送信することで、無線基地局の受光素子の出力として、所望の無線信号周波数帯において周波数間隔がそれぞれ中間周波数信号の周波数分だけ異なる３波の無線信号を得ることができる。   According to the first or second aspect of the present invention, by transmitting four optical signals from the optical transmitter, the output of the light receiving element of the wireless base station has a frequency interval of an intermediate frequency signal in a desired wireless signal frequency band. It is possible to obtain three-wave radio signals that differ by the frequency.

無線加入者端末では、これらの高周波無線信号電波をアンテナで受信した後、ダイオードなどの非線形素子により自乗検波し、フィルタを通すことで、局部発振器、つまり無線信号の周波数帯の電気発振器を用意することなく、中間周波数信号を得ることができる。   In a wireless subscriber terminal, after receiving these high-frequency radio signal radio waves with an antenna, a square oscillator is detected by a non-linear element such as a diode, and is passed through a filter to prepare a local oscillator, that is, an electric oscillator in the frequency band of the radio signal. The intermediate frequency signal can be obtained without any problem.

また、請求項３では、無線基地局に所望の無線信号を光信号で送信する光送信器において、単一スペクトルの光信号を発生する単一スペクトル光源と、前記無線信号の周波数の半値に等しい周波数を有する電気搬送波信号を発生する第１の電気発振器と、前記無線信号の周波数と任意の中間周波数信号の周波数との差の半値に等しい周波数を有する電気搬送波信号を発生する第２の電気発振器と、前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第１の光変調器と、前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第２の光変調器と、前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えたことを特徴とする光送信器をもって解決手段とする。   According to a third aspect of the present invention, in an optical transmitter that transmits a desired radio signal to a radio base station as an optical signal, a single spectrum light source that generates a single spectrum optical signal, and equal to half the frequency of the radio signal A first electric oscillator for generating an electric carrier signal having a frequency, and a second electric oscillator for generating an electric carrier signal having a frequency equal to half the difference between the frequency of the radio signal and the frequency of any intermediate frequency signal A first optical modulator that performs carrier-suppressed double-sideband optical modulation on an optical signal output from the single spectrum light source by an electric carrier signal from a first electric oscillator, and the first light A second optical modulator that subjects the optical signal output from the modulator to carrier-suppressed double-sideband optical modulation with an electric carrier signal from the second electric oscillator, and the second optical modulator. Light signal Contrast, the optical transmitter with a solving means is characterized in that a third optical modulator for performing a light intensity modulated by input electrical digital signal.

また、請求項４では、無線基地局に所望の無線信号を光信号で送信する光送信器において、単一スペクトルの光信号を発生する単一スペクトル光源と、前記無線信号の周波数と任意の中間周波数信号の周波数との差の半値に等しい周波数を有する電気搬送波信号を発生する第１の電気発振器と、前記無線信号の周波数の半値に等しい周波数を有する電気搬送波信号を発生する第２の電気発振器と、前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第１の光変調器と、前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第２の光変調器と、前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えたことを特徴とする光送信器をもって解決手段とする。   According to a fourth aspect of the present invention, in an optical transmitter that transmits a desired radio signal to a radio base station as an optical signal, a single-spectrum light source that generates a single-spectrum optical signal; A first electric oscillator for generating an electric carrier signal having a frequency equal to a half value of a difference from a frequency of the frequency signal; and a second electric oscillator for generating an electric carrier signal having a frequency equal to a half value of the frequency of the radio signal. A first optical modulator that performs carrier-suppressed double-sideband optical modulation on an optical signal output from the single spectrum light source with an electric carrier signal from a first electric oscillator, and the first light A second optical modulator that subjects the optical signal output from the modulator to carrier-suppressed double-sideband optical modulation with an electric carrier signal from the second electric oscillator, and the second optical modulator. Light signal Contrast, the optical transmitter with a solving means is characterized in that a third optical modulator for performing a light intensity modulated by input electrical digital signal.

請求項３あるいは４の発明によれば、光送信器から４つの光信号を送信することで、無線基地局の受光素子の出力として、所望の無線信号周波数帯において周波数間隔が中間周波数信号の周波数分だけ異なる２波の無線信号を得ることができる。   According to the third or fourth aspect of the invention, by transmitting four optical signals from the optical transmitter, the frequency interval of the intermediate frequency signal in the desired radio signal frequency band is obtained as the output of the light receiving element of the radio base station. It is possible to obtain two-wave radio signals that differ by the amount.

無線加入者端末では、これらの高周波無線信号電波をアンテナで受信した後、ダイオードなどの非線形素子により自乗検波し、フィルタを通すことで、局部発振器、つまり無線信号の周波数帯の電気発振器を用意することなく、中間周波数信号を得ることができる。   In a wireless subscriber terminal, after receiving these high-frequency radio signal radio waves with an antenna, a square oscillator is detected by a non-linear element such as a diode, and is passed through a filter to prepare a local oscillator, that is, an electric oscillator in the frequency band of the radio signal. The intermediate frequency signal can be obtained without any problem.

以上説明したように、本発明の光送信器により、無線基地局に光信号を送信する広帯域光−無線融合通信システムの無線加入者端末において、無線信号の周波数帯の電気発振器を用意することなく中間周波数信号を得ることが可能となる。   As described above, a wireless subscriber terminal of a broadband optical-wireless communication system that transmits an optical signal to a wireless base station using the optical transmitter of the present invention without preparing an electric oscillator in the frequency band of the wireless signal. An intermediate frequency signal can be obtained.

これにより、無線加入者端末を安価かつ単純なハードウェア構成にすることが可能となる。   Thereby, it becomes possible to make a wireless subscriber terminal into an inexpensive and simple hardware configuration.

＜実施の形態１＞
本発明の第１の実施の形態について、図５、図６、図７のブロック構成図と、図８の電気周波数及び光周波数のスペクトル図を参照して説明する。 <Embodiment 1>
The first embodiment of the present invention will be described with reference to the block configuration diagrams of FIGS. 5, 6, and 7, and the electrical frequency and optical frequency spectrum diagrams of FIG.

図５は本発明の第１の実施の形態の光送信器１を示すブロック構成図であるが、２は伝送する電気ディジタル信号を入力する入力端子、３は単一スペクトル光源、４は電気発振器７からの出力信号（２ｃ）で単一スペクトル光源３の出力光（２ｂ）を搬送波抑圧両側波帯光変調する第１の光変調器、５は電気発振器８からの出力信号（２ｅ）で第１の光変調器４の出力光（２ｄ）を搬送波抑圧両側波帯光変調する第２の光変調器、６は入力端子２から入力される電気ディジタル信号（２ａ）により第２の光変調器５の出力光（２ｆ）を光強度変調する第３の光変調器である。   FIG. 5 is a block diagram showing the optical transmitter 1 according to the first embodiment of the present invention, in which 2 is an input terminal for inputting an electric digital signal to be transmitted, 3 is a single spectrum light source, and 4 is an electric oscillator. The first optical modulator 5 modulates the output light (2b) of the single spectrum light source 3 with the output signal (2c) from the carrier wave-suppressed double-sideband light by the output signal (2c) from the electric wave generator 7 and the output signal (2e) from the electric oscillator 8 A second optical modulator for modulating the output light (2d) of the first optical modulator 4 with a carrier-suppressed double-sideband optical band; and 6, a second optical modulator based on an electric digital signal (2a) input from the input terminal 2 5 is a third optical modulator that modulates the light intensity of the output light (2f).

この光送信器１において、電気発振器７からの出力信号がミリ波帯などの無線信号の周波数（ｆRF）の半値に等しい周波数（ｆRF／２）を有する電気搬送波信号となるようにし、さらに、電気発振器８からの出力信号が任意の中間周波数信号の周波数（ｆIF）の半値に等しい周波数（ｆIF／２）を有する電気搬送波信号となるようにし、第３の光変調器５の出力光変調信号の占有周波数帯域（Ｂ）が中間周波数信号の周波数（ｆIF）よりも小さくなるようにする。 In this optical transmitter 1, an output signal from the electric oscillator 7 is an electric carrier signal having a frequency (f RF / 2) equal to a half value of the frequency (f RF ) of a radio signal such as a millimeter wave band, and The output signal from the electric oscillator 8 is an electric carrier signal having a frequency (f IF / 2) equal to a half value of the frequency (f IF ) of any intermediate frequency signal, and the output of the third optical modulator 5 The occupied frequency band (B) of the optical modulation signal is made smaller than the frequency (f IF ) of the intermediate frequency signal.

上記のようにして光送信器１から送信された光信号（２ｇ）は、図６に示す無線基地局９で受信される。   The optical signal (2g) transmitted from the optical transmitter 1 as described above is received by the radio base station 9 shown in FIG.

無線基地局９は、光信号（２ｇ）を自乗検波して電気信号に変換する受光素子１０と、この受光素子１０の出力電気信号（２ｈ）であるミリ波帯無線信号を電波として送出するアンテナ１１によって構成される。   The radio base station 9 includes a light receiving element 10 that squarely detects an optical signal (2g) and converts it into an electric signal, and an antenna that transmits a millimeter wave band radio signal that is an output electric signal (2h) of the light receiving element 10 as a radio wave. 11.

光送信器１で、電気発振器７からの出力信号が無線信号の周波数（ｆRF）の半値の周波数（ｆRF／２）を有する電気搬送波信号となるようにし、さらに、電気発振器８からの出力信号が中間周波数信号の周波数（ｆIF）の半値の周波数（ｆIF／２）を有する電気搬送波信号となるようにすることで、無線基地局９において、周波数間隔がそれぞれ中間周波数信号の周波数分だけ異なり、また、周波数安定性の高い３波のミリ波帯無線信号（２ｈ：ｆRF＋ｆIF，ｆRF，ｆRF−ｆIF）を得ることができる。 In the optical transmitter 1, the output signal from the electric oscillator 7 is an electric carrier signal having a half value frequency (f RF / 2) of the frequency (f RF ) of the radio signal, and the output from the electric oscillator 8. By setting the signal to be an electric carrier signal having a half-frequency (f IF / 2) of the frequency (f IF ) of the intermediate frequency signal, the radio base station 9 has frequency intervals corresponding to the frequency of the intermediate frequency signal. Only three millimeter-wave band radio signals (2h: f RF + f IF , f RF , f RF −f IF ) with high frequency stability can be obtained.

図７は本発明の第１の実施の形態の無線加入者端末１２を示すブロック構成図である。無線基地局９から送出されたミリ波帯無線信号（２ｈ）はアンテナ１３により受信された後、ミキサダイオードなどの非線形素子を用いた乗算器１４により自乗検波され、さらにこの乗算器の出力電気信号（２ｉ）をフィルタ１５に通すことで、ミリ波帯の電気発振器を用意することなく、中間周波数帯の電気変調信号（２ｊ）を得ることができる。   FIG. 7 is a block configuration diagram showing the wireless subscriber terminal 12 according to the first embodiment of this invention. The millimeter-wave band radio signal (2h) transmitted from the radio base station 9 is received by the antenna 13 and then square-detected by the multiplier 14 using a non-linear element such as a mixer diode, and further, the output electric signal of this multiplier By passing (2i) through the filter 15, it is possible to obtain the electrical modulation signal (2j) in the intermediate frequency band without preparing a millimeter-wave band electric oscillator.

なお、本実施の形態において、電気発振器７で発生する電気搬送波信号と、電気発振器８で発生する電気搬送波信号とを入れ替えても同様な結果が得られる。   In the present embodiment, the same result can be obtained even if the electric carrier signal generated by the electric oscillator 7 and the electric carrier signal generated by the electric oscillator 8 are interchanged.

＜実施の形態２＞
本発明の第２の実施の形態について、図９、図１０、図１１のブロック図と、図１２の電気周波数及び光周波数のスペクトル図を参照して説明する。 <Embodiment 2>
The second embodiment of the present invention will be described with reference to the block diagrams of FIGS. 9, 10, and 11, and the spectrum diagrams of the electrical frequency and the optical frequency in FIG.

図９は本発明の第２の実施の形態の光送信器１８を示すブロック構成図であるが、１９は伝送する電気ディジタル信号を入力する入力端子、２０は単一スペクトル光源、２１は電気発振器２４からの出力信号（３ｃ）で単一スペクトル光源２０の出力光（３ｂ）を搬送波抑圧両側波帯光変調する第１の光変調器、２２は電気発振器２５からの出力信号（３ｅ）で第１の光変調器２１の出力光（３ｄ）。を搬送波抑圧両側波帯光変調する第２の光変調器、２３は入力端子１９から入力される電気ディジタル信号（３ａ）により第２の光変調器２２の出力光（３ｆ）を光強度変調する第３の光変調器である。   FIG. 9 is a block diagram showing an optical transmitter 18 according to a second embodiment of the present invention, in which 19 is an input terminal for inputting an electric digital signal to be transmitted, 20 is a single spectrum light source, and 21 is an electric oscillator. The first optical modulator 22 modulates the output light (3b) of the single spectrum light source 20 with the output signal (3c) from the carrier wave, and the output signal (3e) is the output signal (3e) from the electric oscillator 25. Output light (3d) of one optical modulator 21. The second optical modulator 23 modulates the carrier wave in the double-sideband optical band, and the optical signal 23 modulates the output light (3f) of the second optical modulator 22 by the electric digital signal (3a) input from the input terminal 19. A third optical modulator.

図９の光送信器１８において、電気発振器２４からの出力信号がミリ波帯などの無線信号周波数（ｆRF）の半値に等しい周波数（ｆRF／２）を有する電気搬送波信号となるようにし、さらに、電気発振器２５からの出力信号が無線信号の周波数（ｆRF）と任意の中間周波数信号の周波数（ｆIF）との差（ｆIF−ｆIF）の半値に等しい周波数（（ｆRF−ｆIF）／２）を有する電気搬送波信号となるようにし、第３の光変調器２３の出力光変調信号の占有周波数帯域（Ｂ）が中間周波数信号の周波数（ｆIF）よりも小さくなるようにする。 In the optical transmitter 18 of FIG. 9, an output signal from the electric oscillator 24 is an electric carrier signal having a frequency (f RF / 2) equal to a half value of a radio signal frequency (f RF ) such as a millimeter wave band, further, the output signal from the electric oscillator 25 is a wireless signal frequency (f RF) and any intermediate frequency signal of the frequency (f IF) and the difference (f IF -f IF) of half the frequency equal ((f RF - f IF ) / 2) so that the occupied frequency band (B) of the output optical modulation signal of the third optical modulator 23 is smaller than the frequency (f IF ) of the intermediate frequency signal. To.

上記のようにして光送信器１８から送信された光信号（３ｇ）は、図１０に示す無線基地局２６で受信される。   The optical signal (3g) transmitted from the optical transmitter 18 as described above is received by the radio base station 26 shown in FIG.

無線基地局２６は、光信号（３ｇ）を自乗検波して電気信号に変換する受光素子２７と、この受光素子２７の出力電気信号（３ｈ）であるミリ波帯無線信号を電波として送出するアンテナ２８によって構成される。   The radio base station 26 squarely detects the optical signal (3g) and converts it into an electric signal, and an antenna that transmits a millimeter-wave band radio signal that is an output electric signal (3h) of the light receiving element 27 as a radio wave. 28.

光送信器１８で、電気発振器２４からの出力信号がミリ波帯などの無線信号の周波数（ｆRF）の半値の周波数（ｆRF／２）を有する電気搬送波信号となるようにし、さらに、電気発振２５からの出力信号が無線信号の周波数（ｆRF）と中間周波数信号の周波数（ｆIF）との差（ｆRF−ｆIF）の半値の周波数（（ｆRF−ｆIF）／２）を有する電気搬送波信号となるようにすることで、無線基地局２６において、周波数間隔が中間周波数信号の周波数分だけ異なり、また、周波数安定性の高い２波のミリ波帯無線信号（３ｈ：ｆRF，ｆRF−ｆIF）を得ることができる。 In the optical transmitter 18, the output signal from the electric oscillator 24 is an electric carrier signal having a half value frequency (f RF / 2) of a frequency (f RF ) of a radio signal such as a millimeter wave band. half the frequency of the difference between the output signal from the oscillation 25 is the frequency of the radio signal (f RF) and intermediate frequency signal frequency (f IF) (f RF -f IF) ((f RF -f IF) / 2) In the radio base station 26, the frequency interval differs by the frequency of the intermediate frequency signal and two millimeter-wave band radio signals (3h: f having high frequency stability) are obtained. RF, it is possible to obtain the f RF -f IF).

図１１は本発明の第２の実施の形態の無線加入者端末２９を示すブロック構成図である。無線基地局２６から送出されたミリ波帯無線信号（３ｈ）はアンテナ３０により受信された後、ミキサダイオードなどの非線形素子を用いた乗算器３１により自乗検波され、さらにこの乗算器の出力電気信号（３ｉ）をフィルタ３２に通すことで、ミリ波帯の電気発振器を用意することなく、中間周波数帯の電気変調信号（３ｊ）を得ることができる。   FIG. 11 is a block diagram showing a wireless subscriber terminal 29 according to the second embodiment of this invention. The millimeter-wave band radio signal (3h) transmitted from the radio base station 26 is received by the antenna 30, and then square-detected by a multiplier 31 using a non-linear element such as a mixer diode, and further, an output electric signal of this multiplier By passing (3i) through the filter 32, an electric modulation signal (3j) in the intermediate frequency band can be obtained without preparing an electric oscillator in the millimeter wave band.

なお、本実施の形態において、電気発振器２４で発生する電気搬送波信号と、電気発振器２５で発生する電気搬送波信号とを入れ替えても同様な結果が得られる。   In the present embodiment, the same result can be obtained even if the electric carrier signal generated by the electric oscillator 24 and the electric carrier signal generated by the electric oscillator 25 are interchanged.

従来の光送信器の一例を示すブロック構成図Block configuration diagram showing an example of a conventional optical transmitter 従来の無線基地局の一例を示すブロック構成図Block configuration diagram showing an example of a conventional radio base station 従来の無線加入者端末の一例を示すブロック構成図Block configuration diagram showing an example of a conventional wireless subscriber terminal 従来の光−無線融合通信システムにおける信号スペクトルを示す図The figure which shows the signal spectrum in the conventional optical-wireless fusion communication system 本発明の第１の実施の形態に係る光送信器を示すブロック構成図The block block diagram which shows the optical transmitter which concerns on the 1st Embodiment of this invention 本究明の第１の実施の形態に係る無線基地局を示すブロック構成図Block configuration diagram showing a radio base station according to the first embodiment of the present study 本発明の第１の実施の形態に係る無線加入者端末を示すブロック構成図The block block diagram which shows the radio | wireless subscriber terminal which concerns on the 1st Embodiment of this invention 本究明の第１の実施の形態における信号スペクトルを示す図The figure which shows the signal spectrum in 1st Embodiment of this investigation 本発明の第２の実施の形態に係る光送信器を示すブロック構成図The block block diagram which shows the optical transmitter which concerns on the 2nd Embodiment of this invention 本発明の第２の実施の形態に係る無線基地局を示すブロック構成図The block block diagram which shows the radio base station which concerns on the 2nd Embodiment of this invention 本発明の第２の実施の形態に係る無線加入者端末を示すブロック構成図The block block diagram which shows the wireless subscriber terminal which concerns on the 2nd Embodiment of this invention 本究明の第２の実施の形態における信号スペクトルを示す図The figure which shows the signal spectrum in 2nd Embodiment of this investigation

符号の説明Explanation of symbols

１，１８：光送信器、２，１９：入力端子、３，２０：単一スペクトル光源、４，２１：第１の光変調器、５，２２：第２の光変調器、２３：第３の光変調器、７，８，２４，２５：電気発振器、９，２６：無線基地局、１０，２７：受光素子、１１，１３，２８，３０：アンテナ、１２，２９：無線加入者端末、１４，３１：乗算器、１５，３２：フィルタ、１６，３３：検波器、１７，３４：出力端子。   1, 18: Optical transmitter, 2, 19: Input terminal, 3, 20: Single spectrum light source, 4, 21: First optical modulator, 5, 22: Second optical modulator, 23: Third Optical modulator, 7, 8, 24, 25: electric oscillator, 9, 26: wireless base station, 10, 27: light receiving element, 11, 13, 28, 30: antenna, 12, 29: wireless subscriber terminal, 14, 31: multiplier, 15, 32: filter, 16, 33: detector, 17, 34: output terminal.

Claims (4)

無線基地局に所望の無線信号を光信号で送信する光送信器において、
光周波数ｆｃの単一スペクトルの光信号を発生する単一スペクトル光源と、
前記無線信号の周波数ｆ RF の半値に等しい周波数ｆ RF ／２を有する電気搬送波信号を発生する第１の電気発振器と、
前記無線基地局から送出された電波を受信する無線端末における中間周波数信号の周波数ｆ IF の半値に等しい周波数ｆ IF ／２を有する電気搬送波信号を発生する第２の電気発振器と、
前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ RF ／２及びｆｃ−ｆ RF ／２の光周波数を有する光信号を出力する第１の光変調器と、
前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ RF ／２＋ｆ IF ／２、ｆｃ＋ｆ RF ／２−ｆ IF ／２、ｆｃ−ｆ RF ／２＋ｆ IF ／２及びｆｃ−ｆ RF ／２−ｆ IF ／２の光周波数を有する光信号を出力する第２の光変調器と、
前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えた
ことを特徴とする光送信器。 In an optical transmitter that transmits a desired radio signal as an optical signal to a radio base station,
A single spectrum light source for generating a single spectrum optical signal of optical frequency fc ;
A first electric oscillator for generating an electric carrier signal having a frequency f RF / 2 equal to half the frequency f RF of the radio signal;
A second electric oscillator that generates an electric carrier signal having a frequency f IF / 2 equal to a half value of a frequency f IF of an intermediate frequency signal in a radio terminal that receives a radio wave transmitted from the radio base station ;
Wherein with respect to the optical signal output from a single-spectrum light source, and facilities the double sideband suppressed carrier light modulated by the electrical carrier wave signal from the first electrical oscillator, fc + f RF / 2 and fc-f RF / 2 of the light A first optical modulator that outputs an optical signal having a frequency ;
Wherein with respect to the first optical signal output from the optical modulator, and facilities the double sideband suppressed carrier light modulated by the second electrical carrier signal from an electrical oscillator, fc + f RF / 2 + f IF / 2, fc + f RF / A second optical modulator that outputs an optical signal having optical frequencies of 2-f IF / 2, fc-f RF / 2 + f IF / 2, and fc-f RF / 2-f IF / 2 ,
An optical transmitter comprising: a third optical modulator that performs optical intensity modulation on the optical signal output from the second optical modulator with the input electrical digital signal. 無線基地局に所望の無線信号を光信号で送信する光送信器において、
光周波数ｆｃの単一スペクトルの光信号を発生する単一スペクトル光源と、
前記無線基地局から送出された電波を受信する無線端末における中間周波数信号の周波数ｆ IF の半値に等しい周波数ｆ IF ／２を有する電気搬送波信号を発生する第１の電気発振器と、
前記無線信号の周波数ｆ RF の半値に等しい周波数ｆ RF ／２を有する電気搬送波信号を発生する第２の電気発振器と、
前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ IF ／２及びｆｃ−ｆ IF ／２の光周波数を有する光信号を出力する第１の光変調器と、
前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施し、ｆｃ＋ｆ RF ／２＋ｆ IF ／２、ｆｃ＋ｆ RF ／２−ｆ IF ／２、ｆｃ−ｆ RF ／２＋ｆ IF ／２及びｆｃ−ｆ RF ／２−ｆ IF ／２の光周波数を有する光信号を出力する第２の光変調器と、
前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えた
ことを特徴とする光送信器。 In an optical transmitter that transmits a desired radio signal as an optical signal to a radio base station,
A single spectrum light source for generating a single spectrum optical signal of optical frequency fc ;
A first electric oscillator that generates an electric carrier signal having a frequency f IF / 2 equal to a half value of a frequency f IF of an intermediate frequency signal in a radio terminal that receives radio waves transmitted from the radio base station ;
A second electrical oscillator for generating an electrical carrier signal having a frequency f RF / 2 equal to half the frequency f RF of the radio signal;
Wherein with respect to the optical signal output from a single-spectrum light source, and facilities the double sideband suppressed carrier light modulated by the electrical carrier wave signal from the first electrical oscillator, fc + f IF / 2 and fc-f IF / 2 of the light A first optical modulator that outputs an optical signal having a frequency ;
Wherein with respect to the first optical signal output from the optical modulator, and facilities the double sideband suppressed carrier light modulated by the second electrical carrier signal from an electrical oscillator, fc + f RF / 2 + f IF / 2, fc + f RF / A second optical modulator that outputs an optical signal having optical frequencies of 2-f IF / 2, fc-f RF / 2 + f IF / 2, and fc-f RF / 2-f IF / 2 ,
An optical transmitter comprising: a third optical modulator that performs optical intensity modulation on the optical signal output from the second optical modulator with the input electrical digital signal. 無線基地局に所望の無線信号を光信号で送信する光送信器において、
単一スペクトルの光信号を発生する単一スペクトル光源と、
前記無線信号の周波数の半値に等しい周波数を有する電気搬送波信号を発生する第１の電気発振器と、
前記無線信号の周波数と任意の中間周波数信号の周波数との差の半値に等しい周波数を有する電気搬送波信号を発生する第２の電気発振器と、
前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第１の光変調器と、
前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第２の光変調器と、
前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えた
ことを特徴とする光送信器。 In an optical transmitter that transmits a desired radio signal as an optical signal to a radio base station,
A single-spectrum light source that generates a single-spectrum optical signal;
A first electric oscillator that generates an electric carrier signal having a frequency equal to half the frequency of the radio signal;
A second electrical oscillator that generates an electrical carrier signal having a frequency equal to half the difference between the frequency of the radio signal and the frequency of any intermediate frequency signal;
A first optical modulator that performs a carrier-suppressed double-sideband optical modulation on an optical signal output from the single spectrum light source by an electric carrier signal from a first electric oscillator;
A second optical modulator for subjecting the optical signal output from the first optical modulator to carrier-suppressed double-sideband optical modulation with an electric carrier signal from a second electric oscillator;
An optical transmitter comprising: a third optical modulator that performs optical intensity modulation on the optical signal output from the second optical modulator with the input electrical digital signal. 無線基地局に所望の無線信号を光信号で送信する光送信器において、
単一スペクトルの光信号を発生する単一スペクトル光源と、
前記無線信号の周波数と任意の中間周波数信号の周波数との差の半値に等しい周波数を有する電気搬送波信号を発生する第１の電気発振器と、
前記無線信号の周波数の半値に等しい周波数を有する電気搬送波信号を発生する第２の電気発振器と、
前記単一スペクトル光源から出力された光信号に対し、第１の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第１の光変調器と、
前記第１の光変調器から出力された光信号に対し、第２の電気発振器よりの電気搬送波信号にて搬送波抑圧両側波帯光変調を施す第２の光変調器と、
前記第２の光変調器から出力された光信号に対し、入力された電気ディジタル信号にて光強度変調を施す第３の光変調器とを備えた
ことを特徴とする光送信器。 In an optical transmitter that transmits a desired radio signal as an optical signal to a radio base station,
A single-spectrum light source that generates a single-spectrum optical signal;
A first electrical oscillator that generates an electrical carrier signal having a frequency equal to half the difference between the frequency of the radio signal and the frequency of any intermediate frequency signal;
A second electric oscillator for generating an electric carrier signal having a frequency equal to half the frequency of the radio signal;
A first optical modulator that performs a carrier-suppressed double-sideband optical modulation on an optical signal output from the single spectrum light source by an electric carrier signal from a first electric oscillator;
A second optical modulator for subjecting the optical signal output from the first optical modulator to carrier-suppressed double-sideband optical modulation with an electric carrier signal from a second electric oscillator;
An optical transmitter comprising: a third optical modulator that performs optical intensity modulation on the optical signal output from the second optical modulator with the input electrical digital signal.
JP2003301795A 2003-08-26 2003-08-26 Optical transmitter for optical-wireless communication system Expired - Fee Related JP4102272B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003301795A JP4102272B2 (en) 2003-08-26 2003-08-26 Optical transmitter for optical-wireless communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003301795A JP4102272B2 (en) 2003-08-26 2003-08-26 Optical transmitter for optical-wireless communication system

Publications (2)

Publication Number Publication Date
JP2005073066A JP2005073066A (en) 2005-03-17
JP4102272B2 true JP4102272B2 (en) 2008-06-18

Family

ID=34406311

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003301795A Expired - Fee Related JP4102272B2 (en) 2003-08-26 2003-08-26 Optical transmitter for optical-wireless communication system

Country Status (1)

Country Link
JP (1) JP4102272B2 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4665134B2 (en) * 2005-08-08 2011-04-06 独立行政法人情報通信研究機構 Fourth harmonic generation system using optical carrier suppressed double sideband modulator
JP4540062B2 (en) * 2005-08-30 2010-09-08 日本電信電話株式会社 Optical-wireless fusion communication system and method
JP5024751B2 (en) * 2006-09-21 2012-09-12 独立行政法人情報通信研究機構 Intensity modulator without bias control by phase modulation conversion
CN107492781B (en) * 2017-09-30 2020-05-12 长春理工大学 1.7 mu m wave band broadband picosecond pulse multi-wavelength optical fiber light source
CN107611758B (en) * 2017-09-30 2020-05-12 长春理工大学 Picosecond pulse light source with adjustable wavelength and repetition frequency of 1.7 mu m wave band
CN107706704B (en) * 2017-09-30 2020-05-12 长春理工大学 1.7 mu m wave band picosecond double-pulse optical fiber light source

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2975457B2 (en) * 1991-07-04 1999-11-10 株式会社エイ・ティ・アール光電波通信研究所 Optical transmission system for wireless link
JP4041205B2 (en) * 1997-04-09 2008-01-30 松下電器産業株式会社 Optical transmission system, optical transmitter and optical receiver
JPH11275023A (en) * 1998-03-24 1999-10-08 Communication Research Laboratory Light and radio frequency mixing method and device thereof
JP2000310800A (en) * 1999-02-23 2000-11-07 Atr Adaptive Communications Res Lab Two optical signal generator
JP4151931B2 (en) * 1999-09-13 2008-09-17 株式会社東芝 Wireless communication system, wireless base station and control station
JP2001111498A (en) * 1999-10-05 2001-04-20 Denso Corp Base station and radio communication system
JP2001197039A (en) * 2000-01-12 2001-07-19 Matsushita Electric Ind Co Ltd System and device for optical transmission
JP4624603B2 (en) * 2000-06-29 2011-02-02 パナソニック株式会社 Optical transmission system for radio access and high-frequency optical transmitter

Also Published As

Publication number Publication date
JP2005073066A (en) 2005-03-17

Similar Documents

Publication Publication Date Title
US8135288B2 (en) System and method for a photonic system
JP3981337B2 (en) Optical fiber-radio mixed communication apparatus and method
TWI625586B (en) Communications device with optical injection locking source and related methods
JP2003318823A (en) Method for processing signal of modulated light and device therefor
US20050221772A1 (en) Harmonic mixer and radio communication device having the same
JP4102272B2 (en) Optical transmitter for optical-wireless communication system
US8059968B2 (en) Modulation device for generating optical signal with quadruple frequency and method thereof
CN111965915A (en) Terahertz wave signal generation system and method based on optical frequency comb
JP4541971B2 (en) Optical transmitter for optical-wireless communication system
JP4535423B2 (en) Optical transmitter and optical-radio fusion communication system
JP4116507B2 (en) Optical transmitter for optical-wireless communication system
US9912410B1 (en) Optical radio-frequency down-conversion and remoting
CN112217528B (en) Transmitter, communication system, and electronic device
US7738844B2 (en) Radio communication device
KR100659805B1 (en) Optical transmission system using ossb-modulation and signal transmission method thereof
JP3887327B2 (en) Optical transmitter and optical transmission method
JP4164570B2 (en) Wireless optical fusion communication system and wireless optical fusion communication method
RU2320091C2 (en) Communication system of millimeter and sub-millimeter wave range (variants) and receiver-transmitter for communication system of millimeter and sub-millimeter wave range and method for communication in sub-millimeter wave range
JP7173544B2 (en) radio signal reception system
JP2011077579A (en) Optical transmission system
JP2007158851A (en) Two-way wireless communication system
JP4230888B2 (en) Frequency converter, frequency conversion method, and optical wireless device using the same
KR101048879B1 (en) Apparatus for converting frequency using semiconductor optical amplifier in bi-directional radio-on-fiber system and method thereof
JP4372527B2 (en) Frequency up converter
JP6086535B2 (en) Optical subcarrier frequency converter

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050804

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20070612

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20070710

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20070906

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20080318

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20080321

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110328

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110328

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120328

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130328

Year of fee payment: 5

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

LAPS Cancellation because of no payment of annual fees