JPS63288544A - Digital signal transmitter-receiver - Google Patents
Digital signal transmitter-receiverInfo
- Publication number
- JPS63288544A JPS63288544A JP12251187A JP12251187A JPS63288544A JP S63288544 A JPS63288544 A JP S63288544A JP 12251187 A JP12251187 A JP 12251187A JP 12251187 A JP12251187 A JP 12251187A JP S63288544 A JPS63288544 A JP S63288544A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- digital signal
- signal
- transmission
- converter
- 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
- 230000005540 biological transmission Effects 0.000 claims abstract description 57
- 238000001228 spectrum Methods 0.000 claims abstract description 18
- 238000007493 shaping process Methods 0.000 claims abstract description 12
- 101100381996 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) BRO1 gene Proteins 0.000 abstract 1
- 150000001875 compounds Chemical class 0.000 abstract 1
- 230000006866 deterioration Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
Landscapes
- Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
- Compression Or Coding Systems Of Tv Signals (AREA)
- Time-Division Multiplex Systems (AREA)
- Dc Digital Transmission (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、ＦＭ伝送路を用いたＰＡＭ伝送により離散化
信号と共に時分割多重されたデュオバイナリ伝送デジタ
ル信号を送信するデジタル信号装置及びこのデジタル信
号を受信復号するデジタル信号受信装置に関する。[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a digital transmission system that transmits a duobinary transmission digital signal time-division multiplexed together with a discretized signal by PAM transmission using an FM transmission line. The present invention relates to a signal device and a digital signal receiving device that receives and decodes the digital signal.
（従来の技術）
テレビジョン信号を伝送する方法としては、時間方向に
連続したアナログ信号として伝送する従来方法の他、時
間離散化アナログ信号として伝送する方法（ＰＡＭ伝送
）も考えられる。このＰＡＭ伝送では、隣接するサンプ
ル値信号間での相互干渉をなくすため、その伝送路特性
はいわゆる符号量干渉が発生しない条件であるナイキス
ト条件を満す必要がある。(Prior Art) As a method of transmitting a television signal, in addition to the conventional method of transmitting it as a time-continuous analog signal, there is also a method of transmitting it as a time-discrete analog signal (PAM transmission). In this PAM transmission, in order to eliminate mutual interference between adjacent sample value signals, the transmission path characteristics must satisfy the Nyquist condition, which is a condition under which so-called code amount interference does not occur.
上記ナイキスト条件を満す伝送路特性は、例えばＰＡＭ
伝送により送信される信号のサンプル周波数がｆｌであ
る場合には、第３図（ａ）に示すようなロールオフ係数
にの２乗余弦特性を有したものが必要とされる。このと
き伝送帯域はｆ ｌ ／２ （−６ｄＢ）、（１十ｋ）
ｆｌ （−”）となる。The transmission path characteristics that satisfy the above Nyquist condition are, for example, PAM
When the sample frequency of the signal to be transmitted is fl, a roll-off coefficient having a squared cosine characteristic as shown in FIG. 3(a) is required. At this time, the transmission band is fl /2 (-6dB), (10k)
fl (-”).
ところで、テレビジョン信号は通常、映像信号を含まな
い帰線期間を有している。従来より、この帰線期間を利
用した付加情報の時分割多重伝送が考えられており、ま
た文字多重放送においては既に実現している。By the way, television signals usually have a blanking period in which no video signal is included. Conventionally, time-division multiplex transmission of additional information using this retrace period has been considered, and has already been realized in teletext broadcasting.
そこで上述の伝送路を用いてテレビジョン信号をＰＡＭ
伝送するに際して、その帰線期間にデジタル化された付
加情報を時分割多重伝送することが考えられる。このと
き付加されるデジタル信号のデルタレートをｆｌに設定
して２値伝送すれば、その伝送容量はｆ １［ｂｉｔ／
ｓｅｃ ］となる。この伝送容量は、誤り率が顕著に増
加しない範囲において増大させたいという要求がある。Therefore, using the above-mentioned transmission path, the television signal is converted into PAM.
When transmitting, it is conceivable to time-division multiplex transmit the digitized additional information during the retrace period. If the delta rate of the digital signal added at this time is set to fl and binary transmission is performed, the transmission capacity is f 1 [bit/
sec ]. There is a demand for increasing this transmission capacity within a range where the error rate does not increase significantly.
この要求を満す方法にデュオバイナリ伝送の利用が考え
られる。One possible method to meet this requirement is to use duobinary transmission.
デュオバイナリ伝送方式により２値化する信号の周波数
特性を第３図（ｂ）に示す余弦特性に設定すれば、その
伝送容量はｆ２− （１＋ｋ）ｆｌに拡大される。If the frequency characteristic of the signal to be binarized by the duobinary transmission method is set to the cosine characteristic shown in FIG. 3(b), the transmission capacity will be expanded to f2-(1+k)fl.
（発明が解決しようとする問題点）
さて、ＰＡＭ伝送を実行する際にＦＭ伝送路を用いた場
合には、周知のように受信側において三角雑音が発生子
る。これに対処するため、受信側において送信されてき
た信号に対し、上述した第３図（ｂ）に示した余弦特性
のスペクトル整形を施したとすると、次式で表わされる
Ｓ／Ｎ改善が可能となる。(Problems to be Solved by the Invention) When an FM transmission path is used to perform PAM transmission, as is well known, triangular noise is generated on the receiving side. To deal with this, if the receiving side applies spectrum shaping to the transmitted signal with the cosine characteristic shown in Figure 3(b) above, it is possible to improve the S/N as expressed by the following equation. becomes.
ω ＣＯ５２（π・ωｓ／ω）ｄω
上述のスペクトル整形を受信側で行なうためには、送信
信号は第３図（ｃ）に示すように帯域がｆ２／２で、帯
域内では平坦かつ周波数ｆ２／２で急峻に減衰する特性
を有さなくてはならない。ω CO52(π・ωs/ω)dω In order to perform the above-mentioned spectrum shaping on the receiving side, the transmitted signal has a band of f2/2 as shown in FIG. 3(c), and is flat within the band and has a frequency of f2. It must have the characteristic of steeply attenuating at /2.
ところが、この周波数帯域は前述のＰＡＭ伝送系に要求
される第３図（ａ）の帯域より広いため、このＰＡＭ伝
送系を通過することができない。したがって、上記ＰＡ
Ｍ伝送系を通過させるためには、送信信号の帯域を第３
図（ｃ）の破線で示すように、ｆ２−／２ （ｆ２−−
（１−ｋ）ｆｌ ）に縮小しなければならない。However, since this frequency band is wider than the band shown in FIG. 3(a) required for the above-mentioned PAM transmission system, it cannot pass through this PAM transmission system. Therefore, the above PA
In order to pass the M transmission system, the transmission signal band must be set to the 3rd band.
As shown by the broken line in figure (c), f2−/2 (f2−−
(1-k) fl ).
するとこれに応じてデュオバイナリ伝送されるデジタル
信号の伝送容量も減少することになり、伝送容量の拡大
を図るというデュオバイナリ伝送本来の特長を発揮させ
ることができなくなってしまう。Accordingly, the transmission capacity of the digital signal transmitted due to duobinary transmission also decreases, making it impossible to take advantage of the original feature of duobinary transmission, which is to expand the transmission capacity.
本発明は、上述の問題点に鑑み成されたもので、ＦＭ伝
送路を含むＰＡＭ伝送系において、Ｓ／Ｎ改善度が高く
、しかも伝送容量が劣化しないデジタル信号の送信装置
及び受信装置を提供することを目的とする。The present invention has been made in view of the above-mentioned problems, and provides a digital signal transmitting device and receiving device that has a high degree of S/N improvement and does not deteriorate transmission capacity in a PAM transmission system including an FM transmission line. The purpose is to
［発明の構成コ
（問題点を解決するための手段）
本発明に係るデジタル信号送信装置は、ＰＡＭ伝送系の
サンプリング周波数をｆｌとした場合、離散化信号に付
加するデジタル信号にデュオバイナリ伝送のためのブリ
コーディング処理を施し、次いでこのデジタル信号の帯
域をｆ１／２に制限した後、その周波数をｆｌからｆ２
に変換してＰＡＭ伝送系に合致するように整形し、前記
離散化信号と共に時分割多重伝送する。[Configuration of the Invention (Means for Solving the Problems)] The digital signal transmitting device according to the present invention, when the sampling frequency of the PAM transmission system is fl, performs duobinary transmission on the digital signal added to the discretized signal. Then, after limiting the band of this digital signal to f1/2, the frequency is changed from fl to f2.
The signal is converted into a format that matches the PAM transmission system, and is time-division multiplexed and transmitted together with the discretized signal.
また、本発明に係るデジタル信号受信装置は、上述のデ
ジタル信号を受信し、その周波数をｆｌからｆ２に変換
後、余弦スペクトル整形を施してその復号を果すもので
ある。Further, the digital signal receiving device according to the present invention receives the above-mentioned digital signal, converts its frequency from fl to f2, and then performs cosine spectrum shaping to decode the signal.
（作用）
上記送信装置によれば、周波数ｆ２のデジタル信号をｆ
１／２に帯域制限することにより、周波数ｆ２より低い
周波数ｆｌでサンプリングしてＰＡＭ伝送を行なりでも
折返し歪を発生することがない。(Function) According to the above transmitting device, the digital signal of frequency f2 is transmitted to f
By limiting the band to 1/2, aliasing distortion will not occur even if PAM transmission is performed by sampling at a frequency fl lower than the frequency f2.
また、上記受信装置によれば、受信するデジタ小信号の
周波数をｆｌからｆ２に変換後、ｃｏｓ（π・ｆ１／ｆ
２）の余弦スペクル整形を行なうことで、ＦＭ伝送路の
三角雑音に対して有効なＳ／Ｎ改善を果すとができる。Further, according to the receiving device, after converting the frequency of the digital small signal to be received from fl to f2, cos(π・f1/f
By performing cosine spectral shaping in 2), effective S/N improvement can be achieved against triangular noise in the FM transmission line.
（実施例）
以下、図面を用いて本発明の一実施例を説明する。第１
図に本発明に係るデジタル信号送信装置及び受信装置を
示す。(Example) Hereinafter, an example of the present invention will be described using the drawings. 1st
The figure shows a digital signal transmitting device and a receiving device according to the present invention.
゛ 先ず、送信装置において、デュオバイナリ伝送のた
めのブリコーディング処理が施された周波数ｆ２のデジ
タル信号（１）は、同図（ａ）に示す中心周波数ｆｃ−
ｆ１／２ （ｆｌ ＜ｆ２）の特性を有する低域フィル
タ（２）に導かれ帯域制限される。前記低域フィルタ（
２）の出力する帯域制限デジタル信号（３）は周波数変
換器（４）に供給され、その周波数をｆ２からｆｌに変
換される。周波数変換されたデジタル信号（５）は、離
散化テレビジョン信号（６）と共に時分割多重手段（７
′）に導かれる。上記時分割多重手段（７）は、供給さ
れる前記離散化テレビジョン信号の帰線期間中に前記デ
ジタル信号（５）を付加情報として時分割多重して出力
する。゛ First, in the transmitter, the digital signal (1) of frequency f2, which has been subjected to bricoding processing for duobinary transmission, has a center frequency fc- shown in FIG.
It is led to a low-pass filter (2) having a characteristic of f1/2 (fl < f2) and is band-limited. The low pass filter (
The band-limited digital signal (3) outputted by 2) is supplied to a frequency converter (4), and its frequency is converted from f2 to fl. The frequency-converted digital signal (5) is sent to the time division multiplexing means (7) together with the discretized television signal (6).
’). The time division multiplexing means (7) time division multiplexes the digital signal (5) as additional information and outputs the digital signal (5) during the retrace period of the supplied discretized television signal.
こうして得られた多重信号（８）は、同図（ｂ）に示す
特性の２乗余弦スペクトル整形器（９）に導かれ、ナイ
キスト条件を満すように周波数整形される。周波数整形
後の多重信号（１０）は、Ｄ／Ａ変換器（１１）を介し
てアナログ化されＦＭ伝送路（１２）に送出されＰＡＭ
伝送される。The multiplexed signal (8) thus obtained is guided to a squared cosine spectrum shaper (9) having the characteristics shown in FIG. The multiplexed signal (10) after frequency shaping is converted into an analog signal via a D/A converter (11) and sent to an FM transmission line (12) where it is transmitted to a PAM.
transmitted.
次に受信装置においては、送信信号（１３）をＡ／Ｄ変
換器（１４）によりデジタル化し、復号された離散化テ
レビジョン信号（１５）を得る。Next, in the receiving device, the transmitted signal (13) is digitized by an A/D converter (14) to obtain a decoded discretized television signal (15).
このとき離散化テレビジョン信号中に多重されたデジタ
ル信号は、同図（Ｃ）に示すようにそのスペクトルが周
波数ｆ１／２で折返しを生じるが、歪は発生しない。上
記デジタル信号は周波数変換器（１６）に導かれ、周波
数ｆ２のデジタル信号（１７）に変換される。これによ
りその周波数特性は同図（ｄ）に示すものとなる。前記
デジタル信号（エフ）は余弦スペクトル整形器（１８）
に供給され、同図（ｅ）に示すスペクトルを有するよう
に周波数整形される。これにより前記ＦＭ伝送路（１２
）を介したことによる三角雑音が抑制される。At this time, the spectrum of the digital signal multiplexed into the discretized television signal undergoes aliasing at the frequency f1/2, as shown in FIG. 3(C), but no distortion occurs. The digital signal is guided to a frequency converter (16) and converted into a digital signal (17) of frequency f2. As a result, its frequency characteristics become as shown in FIG. 2(d). The digital signal (F) is processed by a cosine spectrum shaper (18)
and is frequency-shaped to have the spectrum shown in FIG. 3(e). As a result, the FM transmission line (12
) is suppressed.
なお、この余弦スペクトル整形により、理想的なデュオ
バイナリの周波数伝送特性に対して、周波数ｆ１／２か
らｆ２／２のスペクトル成分が欠落してしまうが、実用
上は問題ない。例えば、欠落分が１０％だとしても、こ
のときのアイ開口率は、第２図（ｂ）に示すように理想
的なアイ開口率（同図（ａ））の９０％に達するもので
あり、十分適確にデジタル信号の復号を果すことができ
る。こうして上記余弦スペクトル整形器（１８）の出力
に復号されたデジタル信号（１９）を得ることができる
。Note that due to this cosine spectrum shaping, spectrum components from frequencies f1/2 to f2/2 are missing from the ideal duobinary frequency transmission characteristic, but there is no problem in practical use. For example, even if the missing portion is 10%, the eye opening ratio in this case reaches 90% of the ideal eye opening ratio (see Figure 2(a)), as shown in Figure 2(b). , it is possible to decode digital signals with sufficient accuracy. In this way, a decoded digital signal (19) can be obtained as the output of the cosine spectrum shaper (18).
［発明の効果］
上述した本発明のデジタル信号送信装置によれば、サン
プル周波数ｆｌのＦＭ伝送路を含むＰＡＭ伝送系におい
て、周波数ｆｌよりも高い周波数のデジタル信号を伝送
することが可能であり、伝送容量の拡大を図ることがで
きる。また、本発明のデジタル受信装置によれば、上記
送信装置からのデジタル送信信号を受信し、これに余弦
スペクトル整形を施すことにより、ＦＭ伝送路を介する
ことにより発生する三角雑音を効果的に抑制することが
できる。[Effects of the Invention] According to the digital signal transmitting device of the present invention described above, in a PAM transmission system including an FM transmission line with a sampling frequency fl, it is possible to transmit a digital signal with a frequency higher than the frequency fl, Transmission capacity can be expanded. Further, according to the digital receiving device of the present invention, by receiving the digital transmission signal from the transmitting device and performing cosine spectrum shaping on it, triangular noise generated by passing through the FM transmission path is effectively suppressed. can do.
さらに本発明ではＦＭ変復調前後のベースバンド信号処
理においては、デジタル信号は、これが多重される離散
化テレビジョン信号と全く等価に扱うことができ、特に
多重化信号として格別の処理を施す必要がなく、簡易な
構成により上記デジタル信号の送受信を行なうことがで
きる。Furthermore, in the present invention, in baseband signal processing before and after FM modulation and demodulation, the digital signal can be treated completely equivalently to the discretized television signal to which it is multiplexed, and there is no need to perform any special processing as a multiplexed signal. , the digital signal can be transmitted and received with a simple configuration.
第１図は、本発明の一実施例に係るデジタル信号送信装
置及び受信装置の構成図、第２図は、本発明により受信
復号されるデジタル信号のアイ開口状態を示すア、イパ
ターン図、第３図は、ＰＡＭ伝送路等の周波数特性図で
ある。
（１）・・・デジタル信号、（２）・・・低域フィルタ
、（４）・・・周波数変換器、
（６）・・・離散化テレビジョン信号、（８）・・・多
重信号、（１２）・・・ＦＭ伝送路、（１３）・・・送
信信号、（１６）・・・周波数変換器、（１８）・・・
余弦スペクトル整形器、（１９）・・・復号デジタル信
号。FIG. 1 is a block diagram of a digital signal transmitting device and a receiving device according to an embodiment of the present invention, and FIG. 2 is a pattern diagram showing an eye opening state of a digital signal received and decoded according to the present invention. FIG. 3 is a frequency characteristic diagram of a PAM transmission line, etc. (1)...Digital signal, (2)...Low pass filter, (4)...Frequency converter, (6)...Discretized television signal, (8)...Multiple signal, (12)...FM transmission line, (13)...Transmission signal, (16)...Frequency converter, (18)...
Cosine spectrum shaper, (19)...Decoded digital signal.
Claims (2)
理が施された周波数ｆ２のデジタル信号が供給される中
心周波数ｆ１／２（ｆ１＜ｆ２）の低域フィルタと、こ
の低域フィルタが出力するデジタル信号の周波数をｆ２
からｆ１に変換する周波数変換器とを有し、この周波数
変換器の出力するデジタル信号と周波数ｆ１の離散化信
号とをＦＭ伝送路を用いたＰＡＭ伝送系により時分割多
重伝送することを特徴とするデジタル信号送信装置。(1) A low-pass filter with a center frequency of f1/2 (f1<f2) to which a digital signal of frequency f2 that has been subjected to precoding processing for duobinary transmission is supplied, and a digital signal output by this low-pass filter. The frequency of f2
and a frequency converter for converting from f1 to f1, and time-division multiplex transmission of the digital signal output from the frequency converter and the discretized signal of frequency f1 by a PAM transmission system using an FM transmission line. Digital signal transmitter.
号と共に時分割多重伝送された周波数ｆ１のデュオバイ
ナリ伝送デジタル信号を入力し、その周波数をｆ１から
ｆ２に変換する周波数変換器と、この周波数変換器の出
力するデジタル信号に周波数特性ｃｏｓ（π・ｆ１／ｆ
２）のスペクトル整形を施す余弦スペクトル整形手段と
を有し、この余弦スペクトル整形手段の出力より復号デ
ジタル信号を得ることを特徴とするデジタル信号受信装
置。(2) A frequency converter that inputs a duobinary transmission digital signal of frequency f1, which is time-division multiplexed and transmitted together with a discretized signal by a PAM transmission system using an FM transmission line, and converts the frequency from f1 to f2; The digital signal output from the frequency converter has a frequency characteristic cos(π・f1/f
2) A digital signal receiving apparatus comprising a cosine spectrum shaping means for performing the spectrum shaping described in 2), and obtaining a decoded digital signal from the output of the cosine spectrum shaping means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12251187A JPS63288544A (en) | 1987-05-21 | 1987-05-21 | Digital signal transmitter-receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12251187A JPS63288544A (en) | 1987-05-21 | 1987-05-21 | Digital signal transmitter-receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63288544A true JPS63288544A (en) | 1988-11-25 |
Family
ID=14837661
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12251187A Pending JPS63288544A (en) | 1987-05-21 | 1987-05-21 | Digital signal transmitter-receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63288544A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0584724A2 (en) * | 1992-08-21 | 1994-03-02 | Nec Corporation | Parallel transmission of TDMA sync and data bursts by artificial frequency selective fade and decision feedback equalization |
-
1987
- 1987-05-21 JP JP12251187A patent/JPS63288544A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0584724A2 (en) * | 1992-08-21 | 1994-03-02 | Nec Corporation | Parallel transmission of TDMA sync and data bursts by artificial frequency selective fade and decision feedback equalization |
| EP0584724A3 (en) * | 1992-08-21 | 1996-06-05 | Nec Corporation | Parallel transmission of tdma sync and data bursts by artificial frequency selective fade and decision feedback equalization |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7528753B2 (en) | Codec simultaneously processing multiple analog signals with only one analog-to-digital converter and method thereof | |
| ATE38755T1 (en) | SYSTEM FOR REDUNDANCY-REDUCING DIGITAL TRANSMISSION OF TELEVISION PICTURE SIGNALS. | |
| JPS63237621A (en) | Multiplex carrier wave demodulator | |
| US7068649B2 (en) | Extended bandwidth homePNA system compatible with homePNA 2.0 | |
| US6256302B1 (en) | Method for the common transmission of digital and analogue modulated radio broadcasting and/or television broadcasting signals | |
| US4943849A (en) | Television transmission system having improved separation of audio and video spectra | |
| US7801559B2 (en) | Methods and apparatus for baseband digital spectrum translation (BDST) | |
| US5686966A (en) | Digital data transmission system for transmitting digital data in a predetermined bandwidth without distortion | |
| JPS62501812A (en) | Processing of analog video signals in digital transmission systems | |
| US6806820B1 (en) | Analog reconstruction of a digital signal | |
| JPS63288544A (en) | Digital signal transmitter-receiver | |
| US4109281A (en) | Terminal device for catv | |
| US7453951B2 (en) | System and method for the transmission of an audio or speech signal | |
| EP0420205A2 (en) | Television signal processing apparatus | |
| JP4523248B2 (en) | Audio video wireless transmission device | |
| US7113539B1 (en) | Method and apparatus for performing bandedge equalization | |
| CN210157279U (en) | Coding and modulating integrated machine | |
| US7359456B2 (en) | Communication system and communication device | |
| JP2678692B2 (en) | Digital multiplexing transmission method and transmission / reception device | |
| JP3601646B2 (en) | Band edge equalization method and apparatus | |
| EP0319109A1 (en) | TV broadcasting system for the transmission of a time-division multiplex television signal | |
| JP2847973B2 (en) | Audio PCM broadcast receiver | |
| JPH0426239A (en) | Signal converter | |
| JPH1051774A (en) | Digital video camera with substantially constant rate and transmission system using the same | |
| JPH01259684A (en) | Television signal sending device and receiving device |