JPS61136350A - Carrier wave recovery circuit - Google Patents
Carrier wave recovery circuitInfo
- Publication number
- JPS61136350A JPS61136350A JP59257467A JP25746784A JPS61136350A JP S61136350 A JPS61136350 A JP S61136350A JP 59257467 A JP59257467 A JP 59257467A JP 25746784 A JP25746784 A JP 25746784A JP S61136350 A JPS61136350 A JP S61136350A
- Authority
- JP
- Japan
- Prior art keywords
- carrier wave
- wave
- modulation
- synchronization pattern
- inverse
- 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
- H04L27/22—Demodulator circuits; Receiver circuits
- H04L27/227—Demodulator circuits; Receiver circuits using coherent demodulation
- H04L27/2275—Demodulator circuits; Receiver circuits using coherent demodulation wherein the carrier recovery circuit uses the received modulated signals
- H04L27/2277—Demodulator circuits; Receiver circuits using coherent demodulation wherein the carrier recovery circuit uses the received modulated signals using remodulation
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、PSK変調波の受信装置における搬送波再生
回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a carrier regeneration circuit in a receiving device for PSK modulated waves.
P S K (phase 5hift keying
)変調方式は、一般にデジタル信号を変調する方式の一
種である。P S K (phase 5hift keying
) Modulation method is generally a type of method for modulating digital signals.
例えば、デジタル信号「0」に対応する搬送波の位相に
対してデジタル信号「1」に対応する搬送波の位相を1
80°ずらして被変調波を生成し、−2値の信号を伝送
する場合がある。For example, the phase of the carrier wave corresponding to the digital signal “1” is set to 1 for the phase of the carrier wave corresponding to the digital signal “0”.
There are cases where a modulated wave is generated with a shift of 80 degrees and a -binary signal is transmitted.
このような、PSK変調方式は信号の識別性が良好なた
め、地球上の局どうしが、遠く離れた人工衛星に設けた
中継局を介して、相互に通信する場合に利用される。Since the PSK modulation method has good signal identification, it is used when stations on the earth communicate with each other via relay stations installed on far-off artificial satellites.
ところが、上記PSK変調方式においてその受信側では
受信したPSK変調波から位相変動のない基準搬送波を
再生し、該再生基準搬送波と入力PSK変調波との位相
を比較することによりデジタル信号を復調している。However, in the PSK modulation method described above, the receiving side reproduces a reference carrier wave with no phase fluctuation from the received PSK modulated wave, and demodulates the digital signal by comparing the phase of the reproduced reference carrier wave and the input PSK modulated wave. There is.
本発明は、かかるPSK変調方弐における受信装置の搬
送波再生回路に関する。The present invention relates to a carrier wave regeneration circuit of a receiving device using such PSK modulation method 2.
従来の搬送波再生回路は、第4図に示すように、逆変調
器1と帯域ろ波器2と復調器3とUW検出器4と同期パ
ターン部予測器5から成る。The conventional carrier regeneration circuit includes an inverse modulator 1, a bandpass filter 2, a demodulator 3, a UW detector 4, and a synchronization pattern part predictor 5, as shown in FIG.
上記従来回路においては、先ず復調器3からの復調信号
a+(第5図(^))からユニークワードUWをUW検
出器4によって検出し、パターン部予測器5へUW検出
信号S、を送出する(第5図(B))。In the conventional circuit described above, the UW detector 4 first detects the unique word UW from the demodulated signal a+ (FIG. 5(^)) from the demodulator 3, and sends the UW detection signal S to the pattern part predictor 5. (Figure 5(B)).
上記S、を受信した同期パターン部予測器5は、逆変調
器1へ無変調部予測信号S2を送出することにより逆変
調器1の逆変調動作を停止させる(第5図(C))。The synchronization pattern part predictor 5, which has received the above S, stops the inverse modulation operation of the inverse modulator 1 by sending the non-modulated part prediction signal S2 to the inverse modulator 1 (FIG. 5(C)).
そして、上記逆変調動作停止時に入力したpsK変調波
の同期用パターンCRをフレームフォーマットの先頭部
とする搬送波を基準搬送波とする。Then, a carrier wave whose frame format has the synchronization pattern CR of the psK modulated wave inputted when the inverse modulation operation is stopped is set as a reference carrier wave.
しかし、上記従来回路はその復調器3が正常に動作して
初めて基準搬送波及び基準位相を決定することができる
。However, the conventional circuit described above can determine the reference carrier wave and reference phase only after the demodulator 3 operates normally.
即ち、第6図に示すように、復調器3からの復調信号が
「1」かrOJかの2植体号を例にとると、信号対雑音
比即ちSN比が悪い場合は雑音の影響によって本来NJ
を表すべきものがrOJになり位相が180°異なるこ
とがある(矢印α)。That is, as shown in FIG. 6, if the demodulated signal from the demodulator 3 is "1" or rOJ, and the demodulated signal is ``1'' or rOJ, if the signal-to-noise ratio, that is, the SN ratio is poor, it will be affected by the noise. Originally NJ
What should be expressed becomes rOJ, and the phase may differ by 180° (arrow α).
また、反対に本来rOJを表わすべきものが「1」にな
ることがある(矢印β)。On the other hand, what should originally represent rOJ may become "1" (arrow β).
即ち、低SN沈下では従来回路は搬送波再生動作が不安
定になるという問題点がある。That is, the conventional circuit has a problem in that the carrier wave regeneration operation becomes unstable at low SN sinking.
c問題点を解決するための手段〕
本発明によれば、各デジタル信号を位相が偏位した正弦
波に対応させて変調したPSK変調波を受信し該受信し
たPSK変調波の先頭部に位置する同期用パターンに暴
いて基準位相を仮定して上記PSK変調波を復調するた
めの基準搬送波を逆変調器により再生するようにした搬
送波再生回路において、上記逆変調器の入力端に同期用
パターン検出部が設けられていると共に上記同期用パタ
ーン検出部は無変調の上記同期用パターンのみ通過させ
るろ波器と該同期用パターンを入力してその包絡線を再
現して出力する包絡線検波器と該検波器の出力を入力し
て基準電圧以上の場合に逆変調停止信号を上記逆変調器
に出力する電圧比較器とにより構成され、上記逆変調停
止信号により逆変調動作を停止し上記同期用パターンに
基いて上記基準位相を仮定し上記基準搬送波を再生する
ことを特徴とする搬送波再生回路が提供される。Means for Solving Problem c] According to the present invention, a PSK modulated wave obtained by modulating each digital signal in correspondence with a phase-deviated sine wave is received, and a PSK modulated wave located at the beginning of the received PSK modulated wave is In the carrier wave regeneration circuit, the reference carrier wave for demodulating the PSK modulated wave is regenerated by an inverse modulator by assuming a reference phase by exposing the synchronization pattern to the input terminal of the inverse modulator. A detection section is provided, and the synchronization pattern detection section includes a filter that allows only the unmodulated synchronization pattern to pass through, and an envelope detector that inputs the synchronization pattern and reproduces and outputs its envelope. and a voltage comparator that inputs the output of the detector and outputs an inverse modulation stop signal to the inverse modulator when the output voltage is equal to or higher than the reference voltage. There is provided a carrier wave regeneration circuit characterized in that the reference carrier wave is regenerated by assuming the reference phase based on the reference pattern.
本発明方式は、受信したPSK変調波のうち先頭部に位
置する無変調の同期用パターンのみを通過させる狭帯域
ろ波器を設け、該ろ波器の出力によって逆変調器を停止
させ基準搬送波を再生できるので、従来のように雑音に
影響されることなくかつどのようなフレームフォーマッ
トの通信方式にも適用できる。The method of the present invention is provided with a narrow band filter that passes only the unmodulated synchronization pattern located at the head of the received PSK modulated wave, and uses the output of the filter to stop the inverse modulator and transmit the reference carrier. can be reproduced, so it is not affected by noise like conventional methods and can be applied to communication systems of any frame format.
以下、本発明を実施例により添付図面を参照して説明す
る。Hereinafter, the present invention will be explained by way of examples with reference to the accompanying drawings.
第1図は本発明に係る搬送波再生回路の構成図、第2図
は第1図の動作説明図、第3図は本発明が適用されるP
SK変調方式の説明図である。FIG. 1 is a configuration diagram of a carrier regeneration circuit according to the present invention, FIG. 2 is an explanatory diagram of the operation of FIG. 1, and FIG. 3 is a P
FIG. 2 is an explanatory diagram of the SK modulation method.
第1図の回路は、逆変調器11、帯域ろ波器12、復調
器13及び同期用パターン検出部16から構成されてい
る。The circuit shown in FIG. 1 includes an inverse modulator 11, a bandpass filter 12, a demodulator 13, and a synchronization pattern detection section 16.
上記搬送波再生回路は、受信側に設けられ、受信したP
SK変調波から基準となる搬送波を再生する回路であり
、この再生した基準搬送波と比較して入力変調波からも
とのデジタル信号を復調する。The carrier wave regeneration circuit is provided on the receiving side and receives the received P.
This circuit reproduces a reference carrier wave from the SK modulated wave, and demodulates the original digital signal from the input modulated wave by comparing it with the reproduced reference carrier wave.
ここで、本発明に適用されるPSK変調方式の概略を、
第3図に基いて説明する。Here, an outline of the PSK modulation method applied to the present invention is as follows.
This will be explained based on FIG.
前述したように、P S K (phase 5hif
t keying)変調方式は被変調波がデジタル信号
の場合の変調方式の一種である。As mentioned above, P S K (phase 5hif
The t keying) modulation method is a type of modulation method when the modulated wave is a digital signal.
第3図の2相変調を例にとって説明すれば、デジタル信
号が「0」の場合はある位相の正弦波m+に、デジタル
信号が「1」の場合は上記m、の波形を反転した位相が
180°の正弦波m2に、それぞれ変換し更に周波数の
大きい無線周波数にのせて受信側へ送信する。Taking the two-phase modulation shown in Figure 3 as an example, if the digital signal is "0", the sine wave m+ has a certain phase, and if the digital signal is "1", the inverted phase of the waveform m is the sine wave m+. Each signal is converted into a 180° sine wave m2, and then transmitted to the receiving side on a higher radio frequency.
第3図は2相変調の例であるが、互いに直交した搬送波
をそれぞれ2相変調して加え合わせた4相変調、更にこ
れを組合わせた8相変調なども同様のしくみである。Although FIG. 3 shows an example of two-phase modulation, four-phase modulation in which carrier waves orthogonal to each other are modulated in two phases and added together, and eight-phase modulation in which these are combined are also similar.
一方、受信側では第1図に示す搬送波再生回路により基
準搬送波を再生し、該基準搬送波と入力変調波との位相
差を検出して元デジタル信号を取り出す。On the other hand, on the receiving side, a reference carrier wave is regenerated by the carrier wave regeneration circuit shown in FIG. 1, and the phase difference between the reference carrier wave and the input modulated wave is detected to extract the original digital signal.
第1図の逆変調器11は上記PSK変調波を入力し受信
側と同様の方法で逆に変調をかける装置である。帯域ろ
波器12は再生搬送波の信号対雑音比を改善するための
帯域ろ波器である。復調器13は逆変調器で再生した基
準搬送波と入力変調波を比較して(第3図)もとのデジ
タル信号を復調する装置である。The inverse modulator 11 in FIG. 1 is a device that inputs the PSK modulated wave and inversely modulates it in the same manner as on the receiving side. The bandpass filter 12 is a bandpass filter for improving the signal-to-noise ratio of the recovered carrier wave. The demodulator 13 is a device that demodulates the original digital signal by comparing the input modulated wave with the reference carrier wave reproduced by the inverse modulator (FIG. 3).
また同期用パターン検出部16は受信したPSK変調波
のうち先頭部に存在する無変調の同期用パターンを検出
する装置である。The synchronization pattern detection unit 16 is a device that detects an unmodulated synchronization pattern present at the head of the received PSK modulated wave.
更に、この同期用パターン検出部16は帯域ろ波器16
aと包絡線検波器16bと電圧比較器16cと 4から
構成されている。Furthermore, this synchronization pattern detection section 16 includes a bandpass filter 16.
4, an envelope detector 16b, and a voltage comparator 16c.
上記帯域ろ波器16aは、後述する入力変調波フレーム
(第2図(^))のうちで無変調部分である同期用パタ
ーンCRのみを通過させる狭帯域のる波器である。包絡
線検波器16bは、上記ろ波器16aからの同期用パタ
ーンCRを入力してその包絡線を再現し出力する装置で
ある。電圧比較器16cは、上記入力した同期用パター
ンCRの包絡線の電圧を基準電圧VL (第2図(ζ
))と比較し、71以上のときに逆変調停止信号を出力
する装置である。The bandpass filter 16a is a narrowband filter that passes only the synchronization pattern CR, which is a non-modulated portion, of the input modulated wave frame (FIG. 2(^)), which will be described later. The envelope detector 16b is a device that inputs the synchronization pattern CR from the filter 16a and reproduces and outputs the envelope. The voltage comparator 16c converts the voltage of the envelope of the input synchronization pattern CR into a reference voltage VL (Fig. 2 (ζ
)), this device outputs an inverse modulation stop signal when it is 71 or more.
次に、上記構成を有する第1図の装置の動作を第2図に
基いて説明する。Next, the operation of the apparatus shown in FIG. 1 having the above configuration will be explained based on FIG. 2.
先ず、第2図(^)に示すフレームフオームのPSK変
調波を受信する。First, a PSK modulated wave in the frame form shown in FIG. 2 (^) is received.
参照符号CRは同期用パターン、BTRはビットタイム
用パターン、DATAはデータである。Reference symbol CR is a synchronization pattern, BTR is a bit time pattern, and DATA is data.
上記同期用パターンCRだけは無変調部分でありビット
タイム用パターンBTRからデータDATAまでは変調
部分である。Only the synchronization pattern CR is a non-modulated portion, and the bit time pattern BTR to data DATA are modulated portions.
同期用パターンCRはPSK変調波の先頭部に存在し搬
送波再生回路の高速同期を確立するためのパターンであ
り、BTRはどのような長さで信号が区切られているか
を示すビットタイミング再生回路の同期用のパターンで
ある。The synchronization pattern CR exists at the beginning of the PSK modulated wave and is a pattern for establishing high-speed synchronization of the carrier wave recovery circuit, and the BTR is a pattern of the bit timing recovery circuit that indicates how long the signal is divided. This is a pattern for synchronization.
同期用パターン検出部16の帯域ろ波器16aは狭帯域
ろ波器であり、無変調の同期用パターンCRのみを通過
させる(第2図(B))。The bandpass filter 16a of the synchronization pattern detection section 16 is a narrowband filter, and allows only the unmodulated synchronization pattern CR to pass (FIG. 2(B)).
次に包絡線検波器16bは、入力したパターンCRの包
絡線を再現して出力しく第2図(C1)、次段の電圧比
較器16cに送出する。Next, the envelope detector 16b reproduces the envelope of the input pattern CR and outputs it, as shown in FIG. 2 (C1), and sends it to the next stage voltage comparator 16c.
電圧比較器16cはそあ基準電圧VLと入力した包絡線
検波器16bの出力とを比較しく第2図(C))、PF
y L以上であれば、逆変調停止信号を逆変調器11
へ送出する。The voltage comparator 16c compares the reference voltage VL with the input output of the envelope detector 16b.
If it is greater than y L, the inverse modulation stop signal is sent to the inverse modulator 11.
Send to.
これにより逆変調器1工はその動作を停止して入力変調
波の同期用パターンCRに基いて基準位相を仮定しこの
基準位相に対して逆に変調をかけ基準搬送波を再生する
。この基tjs搬送波をもとに復調器13は入力変調波
を復調する。As a result, the inverse modulator 1 stops its operation, assumes a reference phase based on the synchronization pattern CR of the input modulated wave, and reversely modulates the reference phase to reproduce the reference carrier wave. The demodulator 13 demodulates the input modulated wave based on this base tjs carrier wave.
本発明によれば、受信したPSK変調波のうち先頭部に
位置する無変調の同期用パターンのみを通過させる狭帯
域ろ波器を設け、1亥ろ波器の出力によって逆変調器を
停止させ基準搬送波を再生できるので、従来のように雑
音に影響されることなくかつどのようなフレームフォー
マットの通信方式にも適用できる。According to the present invention, a narrow band filter is provided that passes only the unmodulated synchronization pattern located at the head of the received PSK modulated wave, and the inverse modulator is stopped by the output of the first filter. Since the reference carrier wave can be regenerated, it is not affected by noise unlike conventional methods and can be applied to communication systems of any frame format.
第1図は本発明に係る搬送波再生回路の構成図、第2図
は第1図の動作説明図、第3図はPSK変調方式の説明
図、第4図から第6図までは従来技術の説明図である。
11・・・逆変調器、12・・・帯域ろ波器、13・・
・復調器、 16・・・同期用パターン検出部。FIG. 1 is a configuration diagram of a carrier wave recovery circuit according to the present invention, FIG. 2 is an explanatory diagram of the operation of FIG. 1, FIG. 3 is an explanatory diagram of the PSK modulation method, and FIGS. It is an explanatory diagram. 11... Inverse modulator, 12... Bandpass filter, 13...
- Demodulator, 16... synchronization pattern detection section.
Claims (1)
調したPSK変調波を受信し該受信したPSK変調波の
先頭部に位置する同期用パターンに基いて基準位相を仮
定して上記PSK変調波を復調するための基準搬送波を
逆変調器により再生するようにした搬送波再生回路にお
いて、上記逆変調器の入力側に同期用パターン検出部が
設けられていると共に上記同期用パターン検出部は無変
調の上記同期用パターンのみ通過させるろ波器と該同期
用パターンを入力してその包絡線を再現して出力する包
絡線検波器と該検波器の出力を入力して基準電圧以上の
場合に逆変調停止信号を上記逆変調器に出力する電圧比
較器とにより構成され、上記逆変調停止信号により逆変
調動作を停止し上記同期用パターンに基いて上記基準位
相を仮定し上記基準搬送波を再生することを特徴とする
搬送波再生回路。Receiving a PSK modulated wave in which each digital signal is modulated in correspondence with a sine wave whose phase is shifted, and assuming a reference phase based on a synchronization pattern located at the head of the received PSK modulated wave, the PSK modulation is performed as described above. In a carrier wave regeneration circuit in which a reference carrier wave for demodulating a wave is regenerated by an inverse modulator, a synchronization pattern detection section is provided on the input side of the inverse modulator, and the synchronization pattern detection section is not provided. A filter that allows only the above-mentioned synchronization pattern of modulation to pass; an envelope detector that inputs the synchronization pattern and reproduces and outputs its envelope; and an envelope detector that inputs the output of the detector and detects when the voltage exceeds the reference voltage. and a voltage comparator that outputs an inverse modulation stop signal to the inverse modulator, stops the inverse modulation operation by the inverse modulation stop signal, assumes the reference phase based on the synchronization pattern, and reproduces the reference carrier wave. A carrier wave regeneration circuit characterized by:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59257467A JPS61136350A (en) | 1984-12-07 | 1984-12-07 | Carrier wave recovery circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59257467A JPS61136350A (en) | 1984-12-07 | 1984-12-07 | Carrier wave recovery circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61136350A true JPS61136350A (en) | 1986-06-24 |
Family
ID=17306715
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP59257467A Pending JPS61136350A (en) | 1984-12-07 | 1984-12-07 | Carrier wave recovery circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61136350A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6351752A (en) * | 1986-08-21 | 1988-03-04 | Nec Corp | Carrier recovery device |
-
1984
- 1984-12-07 JP JP59257467A patent/JPS61136350A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6351752A (en) * | 1986-08-21 | 1988-03-04 | Nec Corp | Carrier recovery device |
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