JP2542809B2 - Receiving method - Google Patents
Receiving methodInfo
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- JP2542809B2 JP2542809B2 JP17368785A JP17368785A JP2542809B2 JP 2542809 B2 JP2542809 B2 JP 2542809B2 JP 17368785 A JP17368785 A JP 17368785A JP 17368785 A JP17368785 A JP 17368785A JP 2542809 B2 JP2542809 B2 JP 2542809B2
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- Japan
- Prior art keywords
- level
- code
- correlation
- signal
- threshold value
- Prior art date
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- Expired - Lifetime
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- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
Description
【発明の詳細な説明】 （イ）産業上の利用分野 本発明は位相同期復調方式の通信、例えばスペクトラ
ム拡散通信における受信方式に関するものである。DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a phase synchronization demodulation type communication, for example, a receiving system in spread spectrum communication.
（ロ）従来の技術 従来、情報信号よりも十分広いスペクトラム幅をもつ
例えば２進の擬似雑音信号（Pseudo Noise Code）
（以下、PN符号と称す）で変調されたキャリアを送信
し、受信側では送信側で用いたのと同一のPN符号で変調
された信号のみを選択受信する、所謂スペクトラム拡散
通信が知られている（例えば、電子科学1978年11月号参
照）。(B) Conventional technology Conventionally, for example, a binary pseudo noise code (Pseudo Noise Code) having a spectrum width sufficiently wider than that of the information signal.
A so-called spread spectrum communication is known, in which a carrier modulated by (hereinafter, referred to as PN code) is transmitted, and a receiving side selectively receives only a signal modulated by the same PN code as used on the transmitting side. (For example, see Electronic Science November 1978 issue).
また、最近ではデータの取り込みタイミングなどが容
易に抽出できる方式として、原データをPN符号に変換す
る過程で、PN符号の極性をデータに応じて変調し、送信
するPN符号極性変調方式が提案されている。In addition, recently, as a method for easily extracting the data acquisition timing, a PN code polarity modulation method has been proposed in which the polarity of the PN code is modulated according to the data and transmitted in the process of converting the original data into the PN code. ing.
上記従来のスペクトラム拡散通信における受信方式に
つき第３図及び第４図を参照して説明する。尚、データ
“1"に対応するPN符号をPNC、データ“0"に対応するPN
符号を▲▼と表記する。A receiving method in the above-described conventional spread spectrum communication will be described with reference to FIGS. 3 and 4. The PN code corresponding to the data “1” is the PNC and the PN code corresponding to the data “0” is the PN code.
The symbol is written as ▲ ▼.
図において、（１）は通信線、（２）は通信線（１）
と受信機との結合部、（３）は結合部（２）を介して印
加された受信信号（PN符号）と受信機側で予じめ設定さ
れた基準PN符号との相関をとる、例えばトランスバーサ
ルフィルタよりなる整合フィルタ、（４）は整合フィル
タ（３）からの出力（即ち、受信PN符号と基準PN符号と
の相関度を示す信号）に基づきベースバンドデータを復
調する復調部、（５）は受信PN符号と基準PN符号との位
相を同期させるための位相同期回路である。In the figure, (1) is a communication line, (2) is a communication line (1)
And a receiver, and (3) correlates the received signal (PN code) applied via the connector (2) with the reference PN code preset on the receiver side, for example, A matched filter composed of a transversal filter, (4) a demodulator for demodulating baseband data based on the output from the matched filter (3) (that is, a signal indicating the degree of correlation between the received PN code and the reference PN code), ( 5) is a phase synchronization circuit for synchronizing the phases of the received PN code and the reference PN code.
次に動作について説明する。 Next, the operation will be described.
通信線（１）を介して結合部（２）へ印加された受信
信号（例えばキャリアをPN符号でAM復調した信号）は斯
る結合部（２）にてAM検波され、受信PN符号となされた
後、整合フィルタ（３）に印加され、基準PN符号との相
関が求められる。A reception signal (for example, a signal obtained by AM demodulating a carrier with a PN code) applied to the coupling section (2) via the communication line (1) is AM-detected by the coupling section (2) to be a reception PN code. Then, it is applied to the matched filter (3) and the correlation with the reference PN code is obtained.
ところで、斯る符号間の相関を求める場合、受信PN符
号と基準PN符号との同期をとる必要があるが、通常は送
信側で用いられた拡散符号（PN符号）発生器と同じ系列
の符号を発生する符号発生器を受信側に備え、この符号
発生器の特定の段の出力符号と受信信号との相関が最大
になる点を求めることにより符号同期を達成している。By the way, when obtaining the correlation between such codes, it is necessary to synchronize the received PN code and the reference PN code, but normally the code of the same sequence as the spreading code (PN code) generator used on the transmission side. Code synchronization for achieving code synchronization is achieved by providing a code generator on the receiving side and generating a point where the correlation between the output code of a specific stage of the code generator and the received signal is maximum.
斯様にして同期がとられた符号同志の相関を整合フィ
ルタ（３）にて求めると、その相関出力は第４図（ｂ）
に示す如く等時間間隔の両極パルス列となる。When the matched filter (3) obtains the correlation between the codes thus synchronized, the correlation output is shown in FIG. 4 (b).
As shown in FIG. 5, the bipolar pulse train has equal time intervals.
斯る相関出力は復調部（４）に印加され、第４図
（ｃ）（ｄ）に示す如く予じめ設定された閾値VSHを越
えたときデータ“1"、−VSHを越えたときデータ“0"と
して復調される。Such a correlation output is applied to the demodulation section (4), and when it exceeds the preset threshold V SH as shown in FIGS. 4 (c) and (d), it exceeds the data "1", -V SH . When it is demodulated as data "0".
（ハ）発明が解決しようとする問題点 上記技術によれば、PN符号に基づきベースバンドデー
タの復調を達成することが出来るが、通信線として家庭
内の電灯線を用いた場合には、電灯線に接続される家庭
用電気機器等に起因するノイズやインビーダンス変動に
より整合フィルタ（３）の出力が第４図（ｅ）に示す如
く乱れてしまい、復調部（４）からの復調データは第２
図（ｆ）（ｇ）に示す如く原データとは全く異なったデ
ータとなり、正常な通信を行なうことが出来なくなる。(C) Problems to be Solved by the Invention According to the above technology, it is possible to achieve demodulation of baseband data based on the PN code. The output of the matched filter (3) is disturbed as shown in FIG. 4 (e) due to noise and impedance fluctuations caused by household electric appliances connected to the line, and demodulation data from the demodulation unit (4) is generated. Is the second
As shown in FIGS. (F) and (g), the data becomes completely different from the original data, and normal communication cannot be performed.
そこで、本発明は通信線として電灯線を用いた場合に
もデータの復調を正確且つ確実に達成し得る受信方式を
提供せんとするものである。Therefore, the present invention is to provide a receiving method capable of accurately and surely demodulating data even when a power line is used as a communication line.
（ニ）問題点を解決するための手段 本発明は、一定の周期で送信される２進の疑似雑音符
号（Pseudo Noise Code:以下PN符号と称す）で変調し
た信号を受信する際に、前記PN符号と受信した該信号と
の相関度と、閾値である予め設定された第１レベルと、
の関係により前記信号を復調する受信方法において、前
記相関度が前記第１のレベルより予め高く設定された第
２のレベルを越えた時を起点として、前記閾値を第２の
レベルに設定し、且つ前記周期に基づいた計時動作を開
始すると共に、該計時動作に従って前記閾値を前記第１
のレベルより予め低く設定された第３のレベルに所定時
間だけ変更し、復調することを特徴とする。(D) Means for Solving the Problems The present invention provides the above-mentioned method when receiving a signal modulated by a binary pseudo noise code (hereinafter referred to as PN code) transmitted at a constant cycle. A degree of correlation between the PN code and the received signal, and a preset first level that is a threshold value;
In the reception method of demodulating the signal according to the relationship of, the threshold value is set to the second level with the starting point when the degree of correlation exceeds a second level that is set higher than the first level in advance, In addition, the timing operation based on the period is started, and the threshold value is set to the first value according to the timing operation.
It is characterized in that the level is changed to a third level which is set lower than the level of (1) for a predetermined time and demodulation is performed.
（ホ）作用 本発明に依れば、受信信号と基準信号との相関度を示
す信号のレベルが所定レベル以上となったとき、データ
を復調する過程における閾値を変更する。(E) Operation According to the present invention, the threshold value in the process of demodulating data is changed when the level of the signal indicating the degree of correlation between the received signal and the reference signal exceeds a predetermined level.
また、相関度を示す信号のレベルが所定レベル以上と
なったとき、閾値を第２のレベルに変更すると共に計時
動作を開始し、この計時動作に基づき閾値を一定時間毎
に前記第２のレベル以外のレベルに変更する。Further, when the level of the signal indicating the degree of correlation becomes equal to or higher than a predetermined level, the threshold value is changed to the second level and the time counting operation is started, and based on the time counting operation, the threshold value is set to the second level at regular intervals. Change to a level other than.
（ヘ）実施例 第１図は本発明の一実施例を示す図である。尚、従来
と同一部分には同一図番を附すと共にその説明を省略す
る。(F) Embodiment FIG. 1 shows an embodiment of the present invention. The same parts as those of the conventional one are designated by the same reference numerals and the description thereof will be omitted.
第１図において、（６）は整合フィルタ（３）からの
相関度を示す信号のレベルを判定する相関度判定部、
（７）は相関度判定部（６）からの判定出力によりトリ
ガされる計時回路、（８）は相関度判定部（６）からの
判定出力信号（s1）及び計時回路（７）からの出力信号
（s2）（s3）（s4）に基づき閾値レベルを制御する閾値
制御部である。In FIG. 1, (6) is a correlation degree determination unit for determining the level of the signal indicating the correlation degree from the matched filter (3),
(7) is a timing circuit triggered by the determination output from the correlation degree determination unit (6), (8) is a determination output signal (s 1 ) from the correlation degree determination unit (6) and from the timing circuit (7) The threshold control unit controls the threshold level based on the output signals (s 2 ) (s 3 ) (s 4 ).
次に、動作について説明する。 Next, the operation will be described.
通信線（１）を介して結合部（２）へ印加された受信
信号｛例えば125kHzのキャリアをPN符号でAM変調した信
号〔第２図（ａ）参照〕｝は、結合部（２）にてAM検波
され、受信PN符号となされた後、整合フィルタ（３）に
印加され、基準PN符号との相関が求められる。斯る整合
フィルタ（３）の相関出力を第２図（ｂ）に示す。The received signal (for example, a signal obtained by AM-modulating a 125 kHz carrier with a PN code [see FIG. 2 (a)]) applied to the coupling section (2) via the communication line (1) is fed to the coupling section (2). After being AM-detected and converted into a reception PN code, it is applied to the matched filter (3) to obtain the correlation with the reference PN code. The correlation output of such a matched filter (3) is shown in FIG. 2 (b).
ところで、初期状態において、相関度判定部（６）は
上記整合フィルタ（３）の出力が第１のレベル（VSH1,
−VSH1）以上あるか否かを判定し、また閾値制御部
（８）は復調部（４）の閾値を第１のレベル（VSH1,−V
SH1）となすよう設定されている。By the way, in the initial state, the correlation determining section (6) outputs the output of the matched filter (3) at the first level (V SH1 ,
-V SH1 ) or more, and the threshold controller (8) sets the threshold of the demodulator (4) to the first level (V SH1 , -V).
SH1 ) is set.
斯る状態において、第２図に示す如く時刻t1で整合フ
ィルタ（３）の出力が第１のレベル（VSH1,−VSH1）を
越えると、相関度判定部（６）からの判定出力信号
（s5）により位相同期回路（５）が駆動され、それ以降
の受信信号と基準PN符号との位相を同期させる。In such a state, when the output of the matched filter (3) exceeds the first level (V SH1 , -V SH1 ) at time t 1 as shown in FIG. 2, the judgment output from the correlation degree judgment unit (6) The phase synchronization circuit (5) is driven by the signal (s 5 ), and the phases of the subsequent received signal and the reference PN code are synchronized.
また、復調部（４）では、整合フィルタ（３）の出力
と閾値（VSH1,−VSH1）との関係により整合フィルタ
（３）の出力がVSH1を越えたときにはデータ“1"、−V
SH1を越えたときにはデータ“0"として復調する〔第２
図（ｃ）（ｄ）参照〕。Further, the demodulation unit (4), the matched filter (3) and the output of the threshold value (V SH1, -V SH1) data "1" when the output of the matched filter (3) exceeds V SH1 the relationship between, - V
When it exceeds SH1 , it is demodulated as data "0" [second
See FIGS. (C) and (d)].
斯る状態において、例えば時刻t2で、整合フィルタ
（３）の出力が第１のレベル（VSH1,−VSH1）より大な
る第２のレベル（VSH2,−VSH2）を越えると、相関度判
定部（６）は判定出力信号（s1）（s6）を出力し、この
判定出力信号（s6）にて計時回路（７）をトリガして計
時動作を開始すると共に判定出力信号（s1）にて閾値制
御部（８）を制御して復調部（４）の閾値を第２のレベ
ル（VSH2,−VSH2）に設定する。In such a state, for example, at time t 2 , when the output of the matched filter (3) exceeds the second level (V SH2 , −V SH2 ) which is higher than the first level (V SH1 , −V SH1 ), The correlation determining unit (6) outputs the determination output signals (s 1 ) (s 6 ) and the determination output signal (s 6 ) triggers the timing circuit (7) to start the timing operation and determine the determination output. The threshold value control unit (8) is controlled by the signal (s 1 ) to set the threshold value of the demodulation unit (4) to the second level (V SH2 , −V SH2 ).
前記計時回路（７）の計時動作が進み、所定時間（例
えば、PN符号−周期に相当する時間）経過すると、第２
図（ｅ）に示す如くカウントアップ信号が出力される。
斯るカウントアップ信号（s2）に基づき閾値制御部
（８）は、復調部（４）の閾値を第１のレベルよりも小
なる第３のレベル（VSH3,−VSH3）となるよう制御す
る。その後、PN符号の１ビットに相当する時間経過する
と、計時回路（７）は再度計時動作状態になると共に信
号（s3）を出力する。斯る信号（s3）は閾値制御部
（８）へ印加され、復調部（４）の閾値を再び第２のレ
ベル（VSH2,−VSH2）に設定する。When the timekeeping operation of the timekeeping circuit (7) progresses and a predetermined time (for example, a time corresponding to the PN code-cycle) elapses, the second
A count-up signal is output as shown in FIG.
Based on the count-up signal (s 2 ), the threshold control unit (8) sets the threshold value of the demodulation unit (4) to the third level (V SH3 , −V SH3 ) which is smaller than the first level. Control. After that, when a time corresponding to one bit of the PN code has elapsed, the time counting circuit (7) again becomes in the time counting operation state and outputs the signal (s 3 ). Such signal (s 3 ) is applied to the threshold control unit (8), and the threshold value of the demodulation unit (4) is set again to the second level (V SH2 , −V SH2 ).
即ち、整合フィルタ（３）の出力が第２のレベル（V
SH2,−VSH2）を越えた後は、所定時間窓を通して相関値
を判定し、その結果に基づいてデータを復調する。That is, the output of the matched filter (3) is at the second level (V
After exceeding SH2 , -VSH2 ), the correlation value is judged through a predetermined time window, and the data is demodulated based on the result.
また、一定時間（例えばデータ３ビットに相当する時
間）復調出力が存在しない場合には、計時回路（７）の
動作を停止させる。斯る計時回路（７）の停止に伴う計
時回路（７）からの出力信号（s7）にて位相同期回路
（５）の動作を停止させると共に出力信号（s4）にて閾
値制御部（８）をリセットし、復調部（４）の閾値を第
１のレベル（VSH1,−VSH1）に設定する。If no demodulated output is present for a certain period of time (for example, a period of time corresponding to 3 bits of data), the operation of the clock circuit (7) is stopped. Threshold controller by the output signal (s 4) stops the operation of the output signal phase synchronizing circuit at (s 7) (5) from the clock circuit associated with the stopping of斯Ru timer circuit (7) (7) ( 8) is reset and the threshold value of the demodulation unit (4) is set to the first level (V SH1 , -V SH1 ).
以上、本発明をスペクトラム拡散通信に適用した場合
につき説明したが、他の位相同期復調方式の通信にも適
用出来ることは云うまでもない。The case where the present invention is applied to spread spectrum communication has been described above, but it goes without saying that the present invention can also be applied to communication using other phase synchronization demodulation methods.
（ト） 発明の効果 本発明に依れば、受信信号と基準信号との相関を求
め、この求められた相関度を示す信号のレベルが所定レ
ベル以上となったとき、データ復調に適応される閾値を
変更するようにしたので、データの誤復調を防止するこ
とが出来る。(G) Effect of the Invention According to the present invention, the correlation between the received signal and the reference signal is obtained, and when the level of the signal indicating the obtained degree of correlation becomes equal to or higher than a predetermined level, it is adapted to data demodulation. Since the threshold value is changed, erroneous demodulation of data can be prevented.
また、受信信号と基準信号との相関を求め、この求め
られた相関度を示す信号のレベルが所定レベル以上とな
ったとき、データ復調に適応される閾値を変更すると共
に計時動作を開始させ、この計時動作に基づき一定時間
毎に再度閾値を変更するようにしたので、データの誤復
調や抜けがなくなり、非常に伝送特性の悪い通信路（例
えば、電灯線）においても正確な通信を達成することが
出来る。Further, the correlation between the received signal and the reference signal is obtained, and when the level of the signal indicating the obtained degree of correlation becomes equal to or higher than a predetermined level, the threshold adapted to the data demodulation is changed and the timing operation is started, Since the threshold value is changed again at regular intervals based on this timing operation, erroneous data demodulation and omissions are eliminated, and accurate communication is achieved even in a communication path with extremely poor transmission characteristics (for example, power line). You can
第１図は本発明の一実施例を示す図、第２図はその各部
波形図、第３図は従来例を示す図、第４図はその各部波
形部である。 （３）……整合フィルタ、（４）……復調部、（６）…
…相関度判定部、（７）……計時回路、（８）……閾値
制御部。FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a waveform diagram of each part thereof, FIG. 3 is a diagram showing a conventional example, and FIG. 4 is a waveform part of each part. (3) ... matched filter, (4) ... demodulation section, (6) ...
... Correlation degree determination unit, (7) ... Timer circuit, (8) ... Threshold control unit.
Claims (1)
号（Pseudo Noise Code:以下PN符号と称す）で変調し
た信号を受信する際に、前記PN符号と受信した該信号と
の相関度と、閾値である予め設定された第１レベルと、
の関係により前記信号を復調する受信方法において、 前記相関度が前記第１のレベルより予め高く設定された
第２のレベルを越えた時を起点として、前記閾値を第２
のレベルに設定し、且つ前記周期に基づいた計時動作を
開始すると共に、該計時動作に従って前記閾値を前記第
１のレベルより予め低く設定された第３のレベルに所定
時間だけ変更し、復調することを特徴とする受信方法。1. When receiving a signal modulated by a binary pseudo noise code (hereinafter referred to as PN code) transmitted at a constant cycle, the correlation between the PN code and the received signal. Degree and a preset first level that is a threshold,
In the receiving method of demodulating the signal according to the relationship, the threshold value is set to the second threshold value when the correlation level exceeds a second level set in advance higher than the first level.
At the same time and starts the timing operation based on the cycle, and according to the timing operation, the threshold value is changed to the third level preset lower than the first level for a predetermined time and demodulated. A reception method characterized in that
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17368785A JP2542809B2 (en) | 1985-08-07 | 1985-08-07 | Receiving method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17368785A JP2542809B2 (en) | 1985-08-07 | 1985-08-07 | Receiving method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6297434A JPS6297434A (en) | 1987-05-06 |
| JP2542809B2 true JP2542809B2 (en) | 1996-10-09 |
Family
ID=15965241
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17368785A Expired - Lifetime JP2542809B2 (en) | 1985-08-07 | 1985-08-07 | Receiving method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2542809B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0335634A (en) * | 1989-07-03 | 1991-02-15 | Clarion Co Ltd | Spread spectrum receiver |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58197935A (en) * | 1982-05-14 | 1983-11-17 | Hitachi Ltd | Spread spectrum receiver |
| JPS59169244A (en) * | 1983-03-17 | 1984-09-25 | Hitachi Denshi Ltd | Synchronism deciding device |
-
1985
- 1985-08-07 JP JP17368785A patent/JP2542809B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6297434A (en) | 1987-05-06 |
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