JPS6025936B2 - code conversion circuit - Google Patents
code conversion circuitInfo
- Publication number
- JPS6025936B2 JPS6025936B2 JP52052823A JP5282377A JPS6025936B2 JP S6025936 B2 JPS6025936 B2 JP S6025936B2 JP 52052823 A JP52052823 A JP 52052823A JP 5282377 A JP5282377 A JP 5282377A JP S6025936 B2 JPS6025936 B2 JP S6025936B2
- Authority
- JP
- Japan
- Prior art keywords
- path
- signal
- phase
- demodulated output
- output signal
- 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
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
- H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Description
【発明の詳細な説明】
本発明は、多値重畳変調方式の符変換回路に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a code conversion circuit using a multilevel superposition modulation method.
変調方式の一方式として、第1パスと対する4相変調信
号に、第2パスと称する前記第1パスの例えば半分の振
幅の4相変調信号を加え合せて同時に送信する多値重畳
変調方式に既に提案されている。One of the modulation methods is a multi-level superimposition modulation method in which a four-phase modulated signal for the first path is added with a four-phase modulated signal having, for example, half the amplitude of the first path, called a second path, and transmitted simultaneously. Already proposed.
この変調方式による変調及び復調装置は、例えば第1図
に示す構成を有するものである。即ち第1パスPIの入
力信号IN1,IN2を4相変調器MODIに、又第2
バスP2の力信号INI′,M2′を4相変調器MOD
2にそれぞれ加えて、搬送波発生器にRGからの搬送波
を4相位相変調する。この4相変調器MODIの出力4
変調信号と、4相変調器MOD2の出力の4相変調信号
を減衰器ANにより振幅を半分に減衰させた信号とを和
回路ADに於いて加え合せて送信するものである。この
送信変調信号のベクトルは第2図に示すものとなり、o
印で示す1針直となる。A modulation and demodulation device using this modulation method has the configuration shown in FIG. 1, for example. That is, the input signals IN1 and IN2 of the first path PI are input to the four-phase modulator MODI, and
The force signals INI', M2' of bus P2 are applied to the four-phase modulator MOD.
2, respectively, and the carrier wave from RG is subjected to four-phase phase modulation to the carrier wave generator. Output 4 of this four-phase modulator MODI
The modulated signal and a signal obtained by attenuating the amplitude of the four-phase modulated signal output from the four-phase modulator MOD2 to half by an attenuator AN are combined in a sum circuit AD and then transmitted. The vector of this transmitted modulated signal is shown in Figure 2, and o
One stitch will be straight as shown by the mark.
なお〔 〕内は第1パスPIの入力信号IN1,IN2
の組合せ、( )内は第2パスP2の入力信号INI′
、瓜2′の組合せを示すものである。受信側に於いては
、変調信号が4相復調器DEM1、位相比較器FD、差
回路SBにそれぞれ加えられ、4相復調器OEM1によ
り第1パスPIの出力信号OUT1,OUT2が復調さ
れる。Note that the numbers in [ ] are the input signals IN1 and IN2 of the first path PI.
The combination of () is the input signal INI' of the second path P2.
, shows the combination of melon 2'. On the receiving side, the modulated signal is applied to a four-phase demodulator DEM1, a phase comparator FD, and a difference circuit SB, and the output signals OUT1 and OUT2 of the first path PI are demodulated by the four-phase demodulator OEM1.
電圧制御発振器VC○、低域炉波器LPF、位相比較器
PD、4相復調器OEM1、4相変調器MODにより搬
送波が再生され、この再生搬送波が4相復調器DEM1
,DEM2にそれぞれ復調用の搬送波として加えられる
。又第1パスPIの復調出力信号は4相変調器MODな
於いて再び4相変調信号となり、その4相変調信号は位
相比較器POと差回路SBとに加えられ、叢回路SBに
於いて、受信変調信号から4相変調器MODの出力の4
相変調信号を引算することにより、第2バスP2の4相
変調信号が得られ、その第2パスP2の4相変調信号を
4相復調器OEM2に於いて復調することにより第2パ
スP2の復調出力信号OUTI′,OUT2′が得られ
る。The carrier wave is regenerated by the voltage controlled oscillator VC○, the low frequency wave generator LPF, the phase comparator PD, the 4-phase demodulator OEM1, and the 4-phase modulator MOD, and this regenerated carrier wave is transmitted to the 4-phase demodulator DEM1.
, DEM2 as carrier waves for demodulation. Also, the demodulated output signal of the first path PI becomes a four-phase modulation signal again in the four-phase modulator MOD, and the four-phase modulation signal is added to the phase comparator PO and the difference circuit SB, and then in the multiplex circuit SB. , 4 of the output of the 4-phase modulator MOD from the received modulated signal
By subtracting the phase modulation signal, a 4-phase modulation signal of the second bus P2 is obtained, and by demodulating the 4-phase modulation signal of the second path P2 in the 4-phase demodulator OEM2, the 4-phase modulation signal of the second bus P2 is obtained. demodulated output signals OUTI' and OUT2' are obtained.
第3図は第1パスの復調アィパターンを示すもので、第
1パスと2パスとの振幅比が紅旧、伝送系の*旧帯城幅
Bとパルス繰返し周期Tとの積がBT=1.0の場合に
ついてもである。Figure 3 shows the demodulation eye pattern of the first pass. The same is true for the case of .0.
前述の如き多億重畳変調方式は、電子簿信学会通信方式
研究会資料 資料番号CS74−1斑「多相多値搬送波
ディジタル信の一方式」(1973年1月29日)に明
されており、例えば1句道の変調に於いても、従来の4
相PSK変復調技術を適用して容易に実現できる利点が
あるものである。The above-mentioned multi-billion superimposed modulation method is disclosed in the Electronic Bookkeeping Society of Japan's Communication Method Research Group, Material No. CS74-1, "A Method of Multiphase Multilevel Carrier Digital Transmission" (January 29, 1973). , for example, in the modulation of one haikudo, the conventional four
This has the advantage that it can be easily realized by applying phase PSK modulation/demodulation technology.
しかし、上述の方法のままであると第1パスの復調デー
タに誤りが生じた場合、第1パスの4相変調器MODに
よる再変調信号も誤ったものとなるから、その誤りが第
2パスに伝搬する欠点が生じる。However, if the above method is used, if an error occurs in the demodulated data of the first pass, the remodulated signal by the four-phase modulator MOD of the first pass will also be incorrect, so that error will be transmitted to the second pass. A defect that propagates occurs.
第1パスの復調デー外こ誤りが生じる確率の一番大きい
点は、第3図の第1パスの復調アィパターンに於いて、
サンプリング点A〜Dのうち、BとCとの点である。即
ち8点とC点とのレベル差が小さいので、第1パスの復
調時の閥値、即ち第3図における相対振中0のレベル、
対てB点をC点又はC点をB点と誤判別する場合が生じ
る。しかるに、A、B、C、0の各レベルに対応づけら
れる第2パスの符号は次のようになる。即ち第2図のベ
クトル図において、Y軸に基準搬送波位相を設定した場
合は、第2パスの4相ベクトルの各々に対応づけられた
2個を1組とする符号の粗たとえば(0、1)(1、1
)等のうち前者が、Y軸に投影されて対応づけられる。
即ち、Aに対応づけられる第2パス符号はY軸の場合“
0”となる。同様に、B、C、0には各々1、0、1が
それぞれ対応づけられる。又、X軸の場合も同様に、0
、1、0、1がA、B、C、0に対応づけれる。The point where the probability of an error occurring outside the demodulated data of the first pass is highest is in the demodulated eye pattern of the first pass shown in Fig. 3.
Among the sampling points A to D, these are points B and C. That is, since the level difference between point 8 and point C is small, the threshold value at the time of demodulation of the first pass, that is, the level of 0 during relative vibration in Fig. 3,
On the other hand, there may be cases where point B is misjudged as point C or point C is misjudged as point B. However, the codes of the second pass associated with each level of A, B, C, and 0 are as follows. In other words, in the vector diagram of FIG. 2, when the reference carrier phase is set on the Y axis, the coarse code, for example (0, 1 ) (1, 1
), etc., the former is projected onto the Y axis and correlated.
In other words, the second pass code associated with A is “
0". Similarly, B, C, and 0 are associated with 1, 0, and 1, respectively. Similarly, in the case of the X axis, 0
, 1, 0, 1 are associated with A, B, C, 0.
従って、BがC、あるいは、CがBに誤ると、第2パス
の号は、B、とCに異なるものが対応づけられているの
で必ず誤ることになる。このことは、第2図のベクトル
図で、最も原点に近い4つの信号に、すべて異なる第2
パス信号が対応づけられていることにつても明らかであ
る。Therefore, if B is mistaken for C or C is mistaken for B, the second pass number will always be incorrect because different things are associated with B and C. This means that in the vector diagram in Figure 2, the four signals closest to the origin all have different second
It is also clear that the path signals are associated.
本発明は、前述の如き多値重畳変調方式に於ける匁点を
改善したもので、その目的は簡単な構成により、第1パ
スの復調データの誤りに対しても、第2パスの復調デー
タの誤りが伝搬しないようにすることである。The present invention improves the momme point in the multilevel convolution modulation method as described above, and its purpose is to provide a simple structure that can prevent errors in demodulated data in the second pass from occurring in the demodulated data in the second pass. The goal is to prevent errors from propagating.
以下実施例については詳細に説明する。第4図は本発明
の実施例の要部ブロック線図であり、MMOD及びMD
EMは第1図に示す送信側の多値変調器及び受信側の多
値復調器、EXRI〜EXR4は排他的オァ回路である
。Examples will be described in detail below. FIG. 4 is a block diagram of main parts of an embodiment of the present invention, and shows MMOD and MD.
EM is a multilevel modulator on the transmitting side and a multilevel demodulator on the receiving side shown in FIG. 1, and EXRI to EXR4 are exclusive OR circuits.
第1パスPIの入力信号IN1,瓜2はそのまま多値変
調器MMODに加えられ、第2パスP2の入力信号川1
′、IN2′は排他的オア回路EXR1、EXR2を介
して多値変調器MMODに加えられる。この排他的オア
回路EXR1,EXR2には第1パスPIの入力信号I
N1,IN2が加えられるので、第2パスP2の入力信
号INI′,IN2′は第1パスPIの入力信号IN1
,州2に従った符号に変換されることになる。第5図は
符号変換により得られる送信変調信号のベクトルを示す
もので、第2パスP2の変調信号はx軸及びy軸に対し
て対称のベクトル関係となる。The input signals IN1 and 2 of the first path PI are directly applied to the multilevel modulator MMOD, and the input signals IN1 and 2 of the second path P2 are applied as they are to the multilevel modulator MMOD.
', IN2' are applied to the multilevel modulator MMOD via exclusive OR circuits EXR1, EXR2. The exclusive OR circuits EXR1 and EXR2 receive the input signal I of the first path PI.
N1 and IN2 are added, so the input signals INI' and IN2' of the second path P2 are the input signal IN1 of the first path PI.
, it will be converted to a code according to State 2. FIG. 5 shows the vector of the transmitted modulated signal obtained by code conversion, and the modulated signal of the second path P2 has a symmetrical vector relationship with respect to the x-axis and the y-axis.
従って復調時に、x軸又はy軸を第1パスPIの復調閥
値レベルとしたとき、第1パスPIの復調デ−夕が“1
”から“0”又は“0”から“1”に誤って得られたと
しても、第2パスP2のデータは正しい状態で保持され
たままとなるから、第1パスPIの復調データの誤りが
第2パスP2に伝搬しないことになる。そして多値復調
器MDEMにより復調された第1パスPIの復調出力信
号OUT1,OUT2はそのまま出力され、第2パスP
2の仮の復調出力信号は、排他的オア回路EXR3,E
XR4により逆変換されて復調出力信号OUT1′,O
UT2′となる。Therefore, during demodulation, when the x-axis or y-axis is set to the demodulation threshold level of the first path PI, the demodulation data of the first path PI is "1".
” to “0” or “0” to “1”, the data on the second pass P2 will remain in the correct state, so the error in the demodulated data on the first pass PI will be avoided. The demodulated output signals OUT1 and OUT2 of the first path PI demodulated by the multilevel demodulator MDEM are output as they are, and are not propagated to the second path P2.
The temporary demodulated output signal of No. 2 is sent to the exclusive OR circuit EXR3,E
Inversely converted by XR4 and demodulated output signals OUT1', O
It becomes UT2'.
以上説明したように、本発明は、第1パスの変調信号と
第2パスの変調信号とを所定のレベル比で重畳する多値
重量変調方式に於いて、第1パスの復調閥値レベルに対
して第2パスの変調信号の内容が対称的になるように、
排他的オア回路等のゲート回路により、第1パスの入力
信号に対応して第2パスの入力信号の符号を変換し、そ
れによって多値重畳変調を行なうものであるから、第1
パスの復調データが誤っても、第2パスの復調データに
は波及しないものとなる。As explained above, the present invention provides a multilevel weighted modulation method in which a modulated signal of the first path and a modulated signal of the second path are superimposed at a predetermined level ratio. On the other hand, so that the content of the modulated signal of the second path is symmetrical,
A gate circuit such as an exclusive OR circuit converts the sign of the input signal of the second path in accordance with the input signal of the first path, thereby performing multilevel superposition modulation.
Even if the demodulated data of the path is erroneous, it will not affect the demodulated data of the second path.
又符号変換の為の構成も排他的オア回路等のゲ−ト回路
で容易に実現できるものである。Further, the configuration for code conversion can be easily realized using a gate circuit such as an exclusive OR circuit.
第1図は多値重畳変調方式の送信変調装置及び受信側復
調装置のブロック線図、第2図は多値重畳変調信号のベ
クトル説明図、第3図は第1パスの復調アィパターン、
第4図は本発明の実施例の要部ブロック線図、第5図は
本発明の実施例の多値重畳変調信号のベクトル説明図で
ある。
PIは第1パス、P2は第2パス、MMODは多値変調
器、MDEMは多値復調器、MDEMは多値復調器、E
XRI〜EXR4は排他的オア回路である。
が1財
が3図
オ2図
が4四
汁5図Fig. 1 is a block diagram of a transmission modulation device and a receiving side demodulation device of a multi-level superposition modulation system, Fig. 2 is a vector explanatory diagram of a multi-level superposition modulation signal, and Fig. 3 is a demodulation eye pattern of the first path.
FIG. 4 is a block diagram of a main part of an embodiment of the present invention, and FIG. 5 is a vector explanatory diagram of a multilevel superimposed modulation signal of an embodiment of the present invention. PI is the first path, P2 is the second path, MMOD is a multi-level modulator, MDEM is a multi-level demodulator, MDEM is a multi-level demodulator, E
XRI to EXR4 are exclusive OR circuits. 1 goods is 3 figures, 2 figures are 4, 4 soups, 5 figures
Claims (1)
とを重畳した多値重畳変調信号のベクトルが、前記第1
パスの復調閾値レベルに対して前記第2“パスの位相変
調信号の内容が対称的になるように、符号変換して前記
多値重畳変調信号を得る方式の復調回路において、受信
変調信号を復調して第1パスの復調出力信号を得るとと
もに該受信復調信号から再生した搬送波を該第1パスの
復調出力信号で変調した信号を該受信変調信号から減算
した信号を復調して第2パスの仮の復調出力信号を得る
多値復調手段と、該第2パスの仮の復調出力信号と該第
1パスの復調出力信号との排他的論理和をとつて第2パ
スの復調出力信号を得るゲート回路とを具えたことを特
徴とする符号変換回路。1 A vector of a multi-level superimposed modulation signal obtained by superimposing the phase modulation signal of the first path and the phase modulation signal of the second path is
Demodulating the received modulated signal in a demodulation circuit that performs code conversion to obtain the multilevel superimposed modulated signal so that the content of the phase modulated signal of the second path is symmetrical with respect to the demodulation threshold level of the path. to obtain the demodulated output signal of the first path, and demodulate the signal obtained by subtracting the signal obtained by modulating the carrier wave regenerated from the received demodulated signal with the demodulated output signal of the first path from the received modulated signal, and then demodulate the signal of the second path. multilevel demodulation means for obtaining a temporary demodulated output signal, and obtains a demodulated output signal for the second path by performing an exclusive OR of the temporary demodulated output signal of the second path and the demodulated output signal of the first path; A code conversion circuit characterized by comprising a gate circuit.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP52052823A JPS6025936B2 (en) | 1977-05-09 | 1977-05-09 | code conversion circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP52052823A JPS6025936B2 (en) | 1977-05-09 | 1977-05-09 | code conversion circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS53138213A JPS53138213A (en) | 1978-12-02 |
JPS6025936B2 true JPS6025936B2 (en) | 1985-06-21 |
Family
ID=12925562
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP52052823A Expired JPS6025936B2 (en) | 1977-05-09 | 1977-05-09 | code conversion circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6025936B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0222937A (en) * | 1988-05-17 | 1990-01-25 | Josef Dirr | Method and apparatus for transmitting signals from plurality of information channels through single transmission channel |
-
1977
- 1977-05-09 JP JP52052823A patent/JPS6025936B2/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
JPS53138213A (en) | 1978-12-02 |
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