JPH0411141B2 - - Google Patents
Info
- Publication number
- JPH0411141B2 JPH0411141B2 JP60026393A JP2639385A JPH0411141B2 JP H0411141 B2 JPH0411141 B2 JP H0411141B2 JP 60026393 A JP60026393 A JP 60026393A JP 2639385 A JP2639385 A JP 2639385A JP H0411141 B2 JPH0411141 B2 JP H0411141B2
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- local oscillator
- signal
- circuit
- satellite
- 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 - Lifetime
Links
- 230000005540 biological transmission Effects 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 10
- 238000004891 communication Methods 0.000 description 7
- 238000001228 spectrum Methods 0.000 description 4
- 238000000605 extraction Methods 0.000 description 2
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、簡潔な回路構成で実現し得る、局部
発振器（以下ローカル発振器ともいう）の不安定
性を除去する周波数再送方式に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a frequency retransmission method that eliminates instability of a local oscillator (hereinafter also referred to as a local oscillator), which can be realized with a simple circuit configuration.
第１図は、従来の無線送受信系の構成の例を示
すブロツク図であつて、１は局Ａ、２は局Ｂ、３
は低速度の原発振器、４は局Ａのローカル発振
器、５は周波数コンバータ、６は局ＡのAFC用
発振器、７は変調回路、８はAFC回路、９は復
調回路、１０は上り回線、１１は局Ｂのローカル
発振器、１２は局ＢのAFC用発振器、１３は下
り回線を表わしている。
FIG. 1 is a block diagram showing an example of the configuration of a conventional wireless transmitting/receiving system, in which 1 is station A, 2 is station B, 3 is
is a low-speed source oscillator, 4 is a local oscillator of station A, 5 is a frequency converter, 6 is an AFC oscillator of station A, 7 is a modulation circuit, 8 is an AFC circuit, 9 is a demodulation circuit, 10 is an uplink, 11 12 represents the local oscillator of station B, 12 represents the AFC oscillator of station B, and 13 represents the downlink.
第１図に示すような構成の系においては、送信
側のローカル発振器の周波数変動が送信信号の周
波数変動となり送信されてしまう。従つて、高い
周波数帯を用いる通信においては、ローカル発振
器の安定度が送信信号の安定度に大きく影響す
る。 In a system configured as shown in FIG. 1, frequency fluctuations of the local oscillator on the transmitting side result in frequency fluctuations of the transmission signal, which is transmitted. Therefore, in communications using high frequency bands, the stability of the local oscillator greatly influences the stability of the transmitted signal.
また、多くの地球局からSCPC信号が送信され
る衛星通信の場合には、各地球局信号の周波数間
隔が厳しく制限される。 Furthermore, in the case of satellite communication in which SCPC signals are transmitted from many earth stations, the frequency interval between each earth station signal is severely restricted.
そのため、何等かの方法で送信周波数の安定化
を図るための周波数制御を行なう必要があつた。 Therefore, it was necessary to perform frequency control in order to stabilize the transmission frequency by some method.
このような目的の周波数制御方式について衛星
通信を例にとり説明する。 A frequency control method for this purpose will be explained using satellite communication as an example.
第２図は衛星回線の構成の例を示すブロツク図
であつて、複数の地球局からのSCPC（Single
Channel Par Carrier）信号が衛星で受信される
衛星回線の場合を示しており、１４はパイロツト
信号発生回路、７は変調回路、１３は下り回線、
１５はパイロツト信号抽出回路、９は復調回路、
１６は送信信号周波数制御回路、１７は周波数制
御信号、１８は受信信号周波数スペクトラム、１
０は上り回線を表わしている。 Figure 2 is a block diagram showing an example of the configuration of a satellite link.
14 is a pilot signal generation circuit, 7 is a modulation circuit, 13 is a downlink,
15 is a pilot signal extraction circuit, 9 is a demodulation circuit,
16 is a transmission signal frequency control circuit, 17 is a frequency control signal, 18 is a reception signal frequency spectrum, 1
0 represents the uplink.
この回線は衛星受信において各地球局からの信
号の周波数を等間隔に整える必要があることか
ら、従来、衛星からパイロツト信号を送り、パイ
ロツト信号を各地球局で抽出し、抽出パイロツト
信号周波数を基に送信信号を周波数制御を行なつ
ていた。 Since this line requires the frequency of signals from each earth station to be arranged at equal intervals during satellite reception, the conventional method is to send a pilot signal from the satellite, extract the pilot signal at each earth station, and then use the extracted pilot signal frequency as the base. The frequency of the transmitted signal was controlled.
上述した従来の数端数制御方式においては、パ
イロツト信号の送受信回路、送信信号周波数制御
回路などの回路を設けなければならず回路構成が
複雑になる欠点があつた。
The above-mentioned conventional fraction control system has the disadvantage that circuits such as a pilot signal transmitting/receiving circuit and a transmitting signal frequency control circuit must be provided, making the circuit configuration complicated.
本発明は、これらの欠点を解決するため、簡潔
な回路構成で実現し得るローカル発振器周波数の
不安定性を容易に除去することのできる回路方式
を提供しようとするもので、送信周波数の安定
化、複数局同時通信における各局信号の相互周波
数変動の低減を図ることを目的としている。 In order to solve these drawbacks, the present invention aims to provide a circuit system that can easily eliminate the instability of the local oscillator frequency, which can be realized with a simple circuit configuration. The purpose is to reduce the mutual frequency fluctuation of each station's signal in simultaneous communication with multiple stations.
以下、本発明の構成等に関し実施例の図面に基
づいて詳細に説明する。 EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be described in detail based on the drawing of an Example.
第３図は本発明の第１の実施例のブロツク図で
あつて、衛星通信の地球局の場合を示したもので
あり、１０は上り回線、１３は下り回線、７は変
調器、５は周波数コンバータ、１９は共通化した
ローカル発振器、９は復調回路、２０は送信信号
キヤリア、２１は送信信号と受信信号の周波数差
を与えるシフトローカル発振器を表わしている。
FIG. 3 is a block diagram of the first embodiment of the present invention, showing the case of an earth station for satellite communication, where 10 is an uplink, 13 is a downlink, 7 is a modulator, and 5 is a downlink. A frequency converter, 19 a common local oscillator, 9 a demodulation circuit, 20 a transmission signal carrier, and 21 a shift local oscillator that provides a frequency difference between the transmission signal and the reception signal.
第３図において、ローカル発振器１９の信号周
波数（周波数FL）の周波数変動値を△FLとした
場合、受信信号（周波数FR）はFR−（FL＋△FL）
に周波数変換され、復調回路９に入力される。復
調回路９でキヤリアを再生された周波数FR−（FL
＋△FL）のキヤリアが変調回路７に出力され、
シフトローカル信号（周波数FS）により送信信号
（周波数FT）と受信信号の周波数差（FS＝FT−
FR）だけ周波数がシフトされる。 In Fig. 3, if the frequency fluctuation value of the signal frequency (frequency F L ) of the local oscillator 19 is △F L , the received signal (frequency F R ) is FR − (F L + △F L )
The signal is frequency-converted and input to the demodulation circuit 9. The frequency F R − (F L
+△F L ) is output to the modulation circuit 7,
The shift local signal (frequency F S ) causes the frequency difference between the transmitted signal (frequency F T ) and the received signal (F S = F T −
The frequency is shifted by F R ).
そして、この信号は再び共通化ローカル発振器
１９の信号によりFR−（FL＋△FL）＋FS＋（FL−△
FL）に周波数変換される。ここで送信信号は、
FT＝FR＋FSとなり、共通化ローカル信号の周波
数変動△FLの影響はなくなる。 Then, this signal is again changed to F R − (F L +△F L ) + F S + (F L −△
F L ). Here the transmitted signal is
F T =F R +F S , and the influence of the frequency fluctuation △F L of the common local signal disappears.
ここで、シフトローカル信号の周波数FSは送受
信信号の周波数に比べ通常１ケタ以上低いため、
FSの周波数変動の値はほとんど無視することがで
きる。 Here, the frequency F S of the shifted local signal is usually more than one digit lower than the frequency of the transmitted and received signals, so
The value of the frequency variation of F S can be almost ignored.
本発明により回路構成においては、上述のよう
に送信信号の生成に際してローカル発振器の周波
数変動が相殺されるから、送信周波数の安定化を
図るための周波数制御回路を設ける必要がない。 In the circuit configuration according to the present invention, the frequency fluctuations of the local oscillator are canceled out when generating the transmission signal as described above, so there is no need to provide a frequency control circuit for stabilizing the transmission frequency.
また、この方式において、下り回線の伝送速度
を速く、上り回線の伝送速度を遅くした場合、下
り回線においてローカル信号の周波数変動により
復調回路の劣化は、変調帯域に対する周波数変動
の相対値が小さいため、小さくなり、さらに上り
回線の送信信号に与える周波数変動も上記方式に
より軽減することができる。 In addition, in this method, when the downlink transmission speed is high and the uplink transmission speed is slow, the demodulation circuit deteriorates due to frequency fluctuations of local signals in the downlink because the relative value of frequency fluctuations with respect to the modulation band is small. , and the frequency fluctuations imparted to uplink transmission signals can also be reduced by the above method.
第４図は第２の実施例のブロツク図であつて、
衛星周波数コンバータにも同様に共通化ローカル
信号発振器を設けた場合を示したもので、２２は
衛星共通ローカル発振回路を表わしている。 FIG. 4 is a block diagram of the second embodiment,
This figure shows a case in which the satellite frequency converter is also provided with a common local signal oscillator, and 22 represents a satellite common local oscillation circuit.
本実施例の構成では、衛星周波数コンバータの
周波数変動をも同様に相殺することができる。 With the configuration of this embodiment, frequency fluctuations of the satellite frequency converter can also be canceled out in the same way.
第５図は第３の実施例のブロツク図であつて、
衛星受信において、各地球局からの信号がFDM
多重される衛星回線を示したもので、２３は衛星
中継器、２４は衛星受信信号スペクトラムを表わ
している。 FIG. 5 is a block diagram of the third embodiment,
In satellite reception, signals from each earth station are FDM
This figure shows the satellite lines to be multiplexed, 23 is a satellite repeater, and 24 is a satellite reception signal spectrum.
本実施例はこのような構成になつているため、
衛星受信における各地球局からの信号周波数の間
隔を安定に保つことが可能となる。 Since this embodiment has such a configuration,
It becomes possible to maintain stable intervals between signal frequencies from each earth station in satellite reception.
以上説明したように、高い周波数帯を用いる通
信において、ローカル発振器の安定度は、送信信
号の安定度に大きく影響し、また、多くの地球局
からSCPC信号が送信される衛星通信では、各地
球局信号の周波数間隔が厳しく制限されるが、本
発明による周波数再送方式を用いた場合には、ロ
ーカル発振器の周波数誤差は装置内に相殺される
から、衛星に受信される各地球局からの受信信号
の周波数差は、上り回線と下り回線の周波数差を
与えるシフトローカル発振器の周波数誤差と、衛
星の位置変動によるドツプラー周波数差から決定
される。
As explained above, in communications using high frequency bands, the stability of the local oscillator greatly affects the stability of the transmitted signal, and in satellite communications where SCPC signals are transmitted from many earth stations, each earth Although the frequency interval of station signals is severely restricted, when using the frequency retransmission method according to the present invention, the frequency error of the local oscillator is canceled within the device, so that the reception from each earth station received by the satellite is The frequency difference of the signals is determined from the frequency error of a shifted local oscillator that provides the frequency difference between uplink and downlink, and the Doppler frequency difference due to positional fluctuations of the satellite.
しかし、実際には上下回線の周波数差は小であ
り、上記の２つの周波数変動値は充分小さいか
ら、安定に各地球局信号の周波数間隔をそろえる
ことができる。 However, in reality, the frequency difference between the upper and lower lines is small, and the above two frequency fluctuation values are sufficiently small, so that the frequency intervals of the earth station signals can be stably aligned.
また、本発明による周波数再送方式は、送信周
波数制御を行なうための周波数検出回路、周波数
制御回路を省略することができるので、ハードの
量を少なくすことができる利点がある。そのた
め、移動地球局など小形な地球局に適している。 Further, the frequency retransmission method according to the present invention has the advantage that the amount of hardware can be reduced because a frequency detection circuit and a frequency control circuit for controlling the transmission frequency can be omitted. Therefore, it is suitable for small earth stations such as mobile earth stations.
第１図は従来の無線送受信系の例を示すブロツ
ク図、第２図は衛星回線の構成の例を示すブロツ
ク図、第３図は本発明の第１の実施例のブロツク
図、第４図は本発明の第２の実施例のブロツク
図、第５図は本発明の第３の実施例のブロツク図
である。
１……局Ａ、２……局Ｂ、３……低速度の原発
振器、４……局Ａのローカル発振器、５……周波
数コンバータ、６……局ＡのAFC用発振器、７
……変調回路、８……AFC回路、９……復調回
路、１０……上り回線、１１……局Ｂのローカル
発振器、１２……局ＢのAFC用発振器、１３…
…下り回線、１４……パイロツト信号発生回路、
１５……パイロツト信号抽出回路、１６……送信
信号周波数制御回路、１７……周波数制御信号、
１８……受信信号周波数スペクトラム、１９……
ローカル発振器、２０……送信信号キヤリア、２
１……シフトローカル発振器、２２……衛星共通
ローカル発振回路、２３……衛星中継器、２４…
…衛星受信信号スペクトラム。
Fig. 1 is a block diagram showing an example of a conventional radio transmission/reception system, Fig. 2 is a block diagram showing an example of a satellite line configuration, Fig. 3 is a block diagram of the first embodiment of the present invention, and Fig. 4. 5 is a block diagram of a second embodiment of the invention, and FIG. 5 is a block diagram of a third embodiment of the invention. 1... Station A, 2... Station B, 3... Low speed original oscillator, 4... Local oscillator of station A, 5... Frequency converter, 6... AFC oscillator of station A, 7
... Modulation circuit, 8 ... AFC circuit, 9 ... Demodulation circuit, 10 ... Uplink, 11 ... Local oscillator of station B, 12 ... AFC oscillator of station B, 13 ...
...downlink, 14...pilot signal generation circuit,
15... Pilot signal extraction circuit, 16... Transmission signal frequency control circuit, 17... Frequency control signal,
18... Received signal frequency spectrum, 19...
Local oscillator, 20... Transmission signal carrier, 2
1...Shift local oscillator, 22...Satellite common local oscillation circuit, 23...Satellite repeater, 24...
...Satellite received signal spectrum.
Claims (1)
部発振器を用いて周波数変換してから搬送波を再
生し、該搬送波を変調した上第２の局部発振器を
用いて周波数をシフトした後、再び前記第１の局
部発振器を用いて周波数変換を行ない送信信号と
して送出する回路を設け、前記第１の局部発振器
を用いて行なう周波数変換は、受信信号を該受信
信号周波数と第１の局部発振器周波数との差の周
波数に変換した場合には、送信信号を前記第２の
局部発振器を用いてシフトして得た信号の周波数
と第１の局部発振器周波数との和の周波数として
生成し、受信信号を該受信信号周波数と第１の局
部発振器周波数との和の周波数に変換した場合に
は、送信信号を前記第２の局部発振器を用いてシ
フトして得た信号の周波数と第１の局部発振器周
波数との差の周波数として生成することを特徴と
する周波数再送方式。1 In a wireless relay system, a received signal is frequency-converted using a first local oscillator, a carrier wave is regenerated, the carrier wave is modulated, the frequency is shifted using a second local oscillator, and then the frequency of the received signal is converted using a first local oscillator. A circuit is provided that performs frequency conversion using a first local oscillator and sends it out as a transmission signal, and the frequency conversion performed using the first local oscillator converts the received signal between the received signal frequency and the first local oscillator frequency. In the case of converting to a difference frequency, the transmitted signal is generated as the sum of the frequency of the signal obtained by shifting using the second local oscillator and the first local oscillator frequency, and the received signal is converted to the difference frequency. When the received signal frequency is converted to a frequency that is the sum of the first local oscillator frequency, the frequency of the signal obtained by shifting the transmitted signal using the second local oscillator and the first local oscillator frequency are A frequency retransmission method characterized by generating a difference frequency between
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2639385A JPS61187428A (en) | 1985-02-15 | 1985-02-15 | Frequency retransmitting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2639385A JPS61187428A (en) | 1985-02-15 | 1985-02-15 | Frequency retransmitting system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61187428A JPS61187428A (en) | 1986-08-21 |
| JPH0411141B2 true JPH0411141B2 (en) | 1992-02-27 |
Family
ID=12192297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2639385A Granted JPS61187428A (en) | 1985-02-15 | 1985-02-15 | Frequency retransmitting system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61187428A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6818254B1 (en) | 1995-01-20 | 2004-11-16 | Engelhard Corporation | Stable slurries of catalytically active materials |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55100780A (en) * | 1979-01-26 | 1980-07-31 | Oki Electric Ind Co Ltd | Television relay broadcasting system |
-
1985
- 1985-02-15 JP JP2639385A patent/JPS61187428A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55100780A (en) * | 1979-01-26 | 1980-07-31 | Oki Electric Ind Co Ltd | Television relay broadcasting system |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6818254B1 (en) | 1995-01-20 | 2004-11-16 | Engelhard Corporation | Stable slurries of catalytically active materials |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61187428A (en) | 1986-08-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |