JPH06507053A - Method and device for differential modulation of signals in multichannel transmission systems - Google Patents
Method and device for differential modulation of signals in multichannel transmission systemsInfo
- Publication number
- JPH06507053A JPH06507053A JP4507989A JP50798992A JPH06507053A JP H06507053 A JPH06507053 A JP H06507053A JP 4507989 A JP4507989 A JP 4507989A JP 50798992 A JP50798992 A JP 50798992A JP H06507053 A JPH06507053 A JP H06507053A
- Authority
- JP
- Japan
- Prior art keywords
- data
- subcarrier
- multiplier
- modulation method
- channel modulation
- 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.)
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Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2602—Signal structure
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
- Mobile Radio Communication Systems (AREA)
- Radio Transmission System (AREA)
- Transmitters (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるため要約のデータは記録されません。 (57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】 多チャネル伝送システムにおける信号の差分変調方法および装置 本発明は、データ流が、周波数領域において順次並んでいる複数のサブキャリア に分割される多チヤネル伝送システム用のデジタル変調方法および装置に関する 。[Detailed description of the invention] Method and device for differential modulation of signals in multichannel transmission systems The present invention provides that a data stream is transmitted over a plurality of subcarriers arranged sequentially in the frequency domain. Relating to a digital modulation method and apparatus for a multichannel transmission system divided into .
本発明は、とりわけ、デジタル放送に使用されるCOFDM (符号化直交周波 数分割多重化) (Coded Orthogonal Frequency Division Multiplexing)方法に使用される。The present invention is particularly applicable to COFDM (coded orthogonal frequency (Several division multiplexing) (Coded Orthogonal Frequency) Division (Multiplexing) method.
デジタルデータ伝送のための多チヤネル変調方法では、伝送すべきデータ流が、 周波数領域において順次並んでいるある数の(例えば数百の)サブキャリアに分 割され、その際サブキャリアのスペクトルは互いに重畳している可能性がある。In multichannel modulation methods for digital data transmission, the data stream to be transmitted is divided into a certain number (for example, hundreds) of subcarriers arranged sequentially in the frequency domain. subcarrier spectra may overlap each other.
この動作様式によって、それぞれのサブキャリアにおいて、本来のデータレート より幾オーダ分も低いデータレートが伝送され、これによりシンボル持続時間は 相応に大きくなる。このことは、伝送チャネルにエコーが生じるとき有利に作用 する。サブキャリアの数を適当に設定することによって、多チヤネル変調方法は 常時、シンボル持続時間が生起い得る最大のエコー遅延伝搬時間に比して太きい ように仕様設計され得る。This mode of operation allows each subcarrier to maintain its original data rate. A data rate that is several orders of magnitude lower is transmitted, so that the symbol duration is It grows accordingly. This is advantageous when echoes occur in the transmission channel. do. By appropriately setting the number of subcarriers, the multichannel modulation method can be The symbol duration is always large compared to the maximum possible echo delay propagation time. The specifications can be designed as follows.
エコーの影響は例えば、シンボルを直ぐ相次いで送信せずに、2つの連続するシ ンボルの間にその都度、最初に送信されたシンボルのエコーが減衰するガードタ イムを設けることによって完全に排除される。The effect of echo is e.g. when two consecutive symbols are transmitted without transmitting them immediately one after the other. A guard tag is used to attenuate the echo of the first transmitted symbol during each symbol. This can be completely eliminated by providing a time frame.
多チヤネル変調方法の技術的な実現手法は例えば、デジタル方法として、例えば 、送信側において送信信号を複合ベースバンドにてまたは中間周波数にて算出す る少なくとも1つのマイクロプロセッサにおけるプログラムとして行われる。合 公知のアナログ技術方法では送信信号を搬送周波数位置にセツティング(変換) することができる。相応に受信機において信号はまずアナログで受信され、それ からベースバンドまたは中間周波数にダウンコンバートされかつそれからデジタ ルで引き続き処理される。The technical realization method of the multi-channel modulation method is, for example, as a digital method, e.g. , the transmitting side calculates the transmitted signal at the composite baseband or at the intermediate frequency. and executed as a program on at least one microprocessor. If Known analog technology methods set (convert) the transmitted signal to the carrier frequency position. can do. Correspondingly, in the receiver the signal is first received in analog form and then downconverted from baseband or intermediate frequency and then digital will continue to be processed in the file.
多チヤネル変調信号は、時間−周波数スロットから成る。タイムスロットは、デ ィスリレートなシンボルクロックによ7て形成され、周波数スロットはサブキャ リアー周波数間隔によって形成される。エコーを減衰するための手段、例えば上 述のガードタイムが設けられているとき、それぞれの時間−周波数スロットにお ける無線チャネルの影響は、減衰および位相回転にある。減衰および位相回転は 通例、時間および周波数可変である。A multi-channel modulated signal consists of time-frequency slots. The time slot is The frequency slot is formed by a frequency-related symbol clock. formed by the rear frequency interval. Means for attenuating echoes, e.g. When the guard time described above is provided, each time-frequency slot The effects of the wireless channel on the transmission are attenuation and phase rotation. Attenuation and phase rotation are Typically time and frequency variable.
多チヤネル信号のサブキャリアに対する変調方法として有利には、公知の位相変 調が使用される。その際種々のデータシンボルは送信信号の種々様々な位相特性 経過として表示される。その場合復調に対して、チャネルにより規定される位相 回転が障害量として作用し、それは適当な手段によって補償しなければならない 。As a modulation method for the subcarriers of a multichannel signal, the known phase shift method is advantageously used. key is used. The different data symbols then depend on the different phase characteristics of the transmitted signal. Displayed as progress. Then for demodulation, the phase defined by the channel The rotation acts as a disturbance quantity, which must be compensated by suitable means. .
公知の方法は、差分復調および差分ブリコーディング(予測符号化)である。こ の場合データは、シンボルの位相そのものとしてではなくて、2つの連続するシ ンボル相互間の位相差として伝送される。多チヤネル方法では、差分復調および ブリコーディング(予測符号化)はそれぞれのサブキャリアにおいて別個に実施 される。Known methods are differential demodulation and differential bricoding (predictive coding). child In the case of It is transmitted as a phase difference between symbols. Multichannel methods involve differential demodulation and Bricoding (predictive coding) is performed separately on each subcarrier be done.
差分ブリコーディング(予測符号化)は送信機において行われ(第1A図)かつ 差分復調は受信機において行われる(第1B図)。Differential precoding (predictive coding) is performed at the transmitter (Figure 1A) and Differential demodulation is performed at the receiver (Figure 1B).
複素数の乗算は、その位相の加算に相応し、共役複素数の形成は、位相の極性の 反転に相応する。“D”は、第1A図、第1B図において1シンボル分の遅延を 表し、*は共役複素成分を表す。The multiplication of complex numbers corresponds to the addition of their phases, and the formation of conjugate complex numbers corresponds to the addition of their phases. Corresponds to reversal. "D" is the delay of one symbol in Figures 1A and 1B. where * represents a conjugate complex component.
差分復調ないし差分ブリコーディングは、チャネルに起因する位相回転が1つの シンボルから後続のシンボルまで変化しないという仮定に基づいている。しかし 時間的に変化する(時変性の)無線チャネルでは、特に比較的長いシンボル持続 時間を有する多チヤネル方法においてこの仮定は満たされないことが多い。その 場合雑音のない状態においてすら伝送エラーが発生する。Differential demodulation or differential bricoding is a method in which the phase rotation due to the channel is one It is based on the assumption that symbols do not change from one symbol to the next. but Relatively long symbol durations, especially in time-varying radio channels This assumption is often not fulfilled in multi-channel methods with time. the In this case, transmission errors occur even in noise-free conditions.
従って本発明の課題は、不安定な無線チャネルの信号の伝送品質が改善される、 多チヤネル伝送システムに対する変調方法および装置を提供することである。Therefore, it is an object of the present invention to improve the transmission quality of unstable wireless channel signals. It is an object of the present invention to provide a modulation method and apparatus for a multi-channel transmission system.
この課題は、請求項1ないし4の特徴部分に記載の構成によって解決される。別 の構成は請求項5に記載されている。This object is achieved by the features described in the characterizing parts of claims 1 to 4. another The structure of is described in claim 5.
次に本発明を実施例につき添付図面を参照して説明する。The present invention will now be described by way of example with reference to the accompanying drawings.
第2図の実施例において、送信側および受信側の装置の部分が複数のサブキャリ ア・・・k−1,に、に+1・・・とともに示されており、それらは送信側およ び受信側においてそれぞれ、隣接するサブキャリアのデータをその都度結合する 乗算器を含んでいる。送信機において例えば、サブキャリアに−1,にの乗算さ れたデータがサブキャリアに+lの乗算器に供給されかつサブキャリアに+lの データと乗算される。受信機側において、サブキャリアに十iのこの信号はサブ キャリアにの共役複素信号と乗算される。この方法は、周波数差分変調と称され る。In the embodiment of FIG. 2, portions of the transmitter and receiver equipment may A... k-1, and +1... are shown, and they are and on the receiving side, the data of adjacent subcarriers are combined each time. Contains a multiplier. For example, in the transmitter, the subcarrier is multiplied by -1, The data sent to the subcarrier is fed to a +l multiplier and the subcarrier is fed to a +l multiplier. Multiplied by data. At the receiver side, this signal with ten i subcarriers The carrier is multiplied by the conjugate complex signal. This method is called frequency difference modulation. Ru.
この装置によって実施される方法は、1・っのサブキャリアから次のサブキャリ アまでチャネルに起因する位相回転が変化しないという仮定に基づいている。こ の仮定は公知の差分変調における仮定に類似しているが、ただ、時間不変性に周 波数不変性が代わっている。しかし多チヤネル変調方法では後者の方がむしろし ばしば生じる。というのは、長いシンボル持続時間にサブキャリアの小さな周波 数間隔が相応するからである。The method implemented by this device is to move from one subcarrier to the next subcarrier. It is based on the assumption that the phase rotation due to the channel does not change until child The assumption is similar to that in the well-known differential modulation, except that Wavenumber invariance has been replaced. However, the latter method is preferable for multi-channel modulation methods. Occurs often. This is because the small frequency of the subcarriers is This is because the number intervals are corresponding.
第3図の別の実施例において、サブキャリアの時間的に連続するデータシンボル 並びに隣接するサブキャリアのデータも相互に結合される、送信側および受信側 の装置が示されている。例えば送信機のサブキャリアに+]において、2つの連 続するデータシンボル相互間の位相差として伝送されるデータが、サブキャリア に−1,にの乗算されたデータとともに乗算器に供給される。受信機において、 サブキャリアに+1のこの乗算された、複素信号がサブキャリアにの共役複素信 号というのは乗算される。引き続いてこの乗算された信号は、時間的に遅延され た、共役複素信号ととともに別の乗算器に供給される。この2回の差分変調によ って、送信機においてサブキャリアの信号がまず差分予備符号化されかつ引き続 いて周波数差分ブリコーディングされかつそれから受信機においてまず差分復調 されかつ引き続いて周波数差分復調される。2回の差分変調は、送信機側並びに 受信機側においてもまず、周波数差分変調および引き続く差分変調によって実施 される。In another embodiment of FIG. 3, temporally consecutive data symbols of subcarriers and the data of adjacent subcarriers are also mutually combined, the transmitter and the receiver equipment is shown. For example, in the transmitter subcarrier +], two consecutive The data transmitted as a phase difference between successive data symbols is is supplied to the multiplier together with the data multiplied by -1 and by. In the receiver, This complex signal multiplied by +1 on the subcarrier becomes the conjugate complex signal on the subcarrier. The numbers are multiplied. This multiplied signal is subsequently delayed in time. It is also supplied to another multiplier together with the conjugate complex signal. These two differential modulations Therefore, at the transmitter, the subcarrier signals are first differentially pre-encoded and then is frequency differentially precoded and then first differentially demodulated at the receiver. and subsequently frequency differential demodulation. The two differential modulations are performed on the transmitter side and On the receiver side, it is also carried out first by frequency difference modulation and then by differential modulation. be done.
2回の差分変調により、従来の差分変調および周波数差分変調にも比べて、それ が、チャネルに起因する位相回転の時間的な不変性の仮定も周波数不変性の仮定 も必要とせず、時間および周波数に関するチャネル位相特性を1つの信号空間特 性平面により近似するという格別な利点が得られる。この近似は、無線チャネル において、時間ないし周波数に関して一定な位相経過による近似よりも著しく良 好である。Due to the two-time differential modulation, compared to conventional differential modulation and frequency differential modulation, However, the assumption of time invariance of the phase rotation due to the channel and the assumption of frequency invariance channel phase characteristics with respect to time and frequency into one signal space characteristic. The particular advantage is that it is more closely approximated by the spatial plane. This approximation is based on the radio channel is significantly better than the approximation by a constant phase course with respect to time or frequency. It's good.
F旧、IA FIG、IB 送信機 受信機 F旧2 送信機 受信機F old, IA FIG, IB Transmitter Receiver F old 2 Transmitter Receiver
Claims (5)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE4114274A DE4114274A1 (en) | 1991-05-02 | 1991-05-02 | METHOD AND ARRANGEMENT FOR DIFFERENTIAL MODULATION OF SIGNALS IN A MULTI-CHANNEL TRANSMISSION SYSTEM |
DE4114274.8 | 1991-05-02 | ||
PCT/EP1992/000841 WO1992020179A1 (en) | 1991-05-02 | 1992-04-14 | Process and arrangement for the differential modulation of signals in a multi-channel transmission system |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH06507053A true JPH06507053A (en) | 1994-08-04 |
Family
ID=6430783
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4507989A Pending JPH06507053A (en) | 1991-05-02 | 1992-04-14 | Method and device for differential modulation of signals in multichannel transmission systems |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0589895A1 (en) |
JP (1) | JPH06507053A (en) |
AU (1) | AU652052B2 (en) |
CA (1) | CA2109211A1 (en) |
DE (1) | DE4114274A1 (en) |
FI (1) | FI934830A0 (en) |
WO (1) | WO1992020179A1 (en) |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
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US7239666B1 (en) | 1994-09-09 | 2007-07-03 | Sony Corporation | Communication system |
JP3577754B2 (en) * | 1994-09-09 | 2004-10-13 | ソニー株式会社 | Communication method and device |
US5649297A (en) * | 1994-10-21 | 1997-07-15 | Seiko Communications Holding N.V. | Transmitting digital data using multiple subcarriers |
FI99252C (en) * | 1995-07-03 | 1997-12-29 | Nokia Mobile Phones Ltd | Combined radio signal modulation and multi-use method |
DE19638654A1 (en) * | 1996-09-20 | 1998-03-26 | Siemens Ag | Digital message transmission method |
DE19719762A1 (en) * | 1997-05-10 | 1998-11-12 | Bosch Gmbh Robert | Process for the transmission of data, as well as transmitter and receiver |
EP0991237A1 (en) * | 1998-09-30 | 2000-04-05 | TELEFONAKTIEBOLAGET L M ERICSSON (publ) | Multicarrier communication method with time-frequency differential encoding |
GB2373148A (en) * | 2001-02-01 | 2002-09-11 | Roke Manor Research | Intra symbol differential modulation of a multi-carrier signal |
GB2383726A (en) * | 2001-12-31 | 2003-07-02 | Calum Ian Bruce Gorton | Dual frequency radian differential information transfer |
US8361045B2 (en) † | 2006-03-10 | 2013-01-29 | Kimberly-Clark Worldwide, Inc. | Apparatus and method for manufacturing several distinct disposable absorbent articles on a single machine |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
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DE4029478C2 (en) * | 1989-09-28 | 1995-08-03 | Siemens Ag | Method for the transmission of data in a bus system |
DE3935911A1 (en) * | 1989-10-27 | 1991-05-02 | Deutsche Forsch Luft Raumfahrt | METHOD FOR RECEIVING BIT DETECTION OF DIFFERENTIALLY CODED BINARY OR QUATERIAL PSK SIGNALS IN DIFFERENTIALLY COHERENT DEMODULATION |
-
1991
- 1991-05-02 DE DE4114274A patent/DE4114274A1/en not_active Withdrawn
-
1992
- 1992-04-14 WO PCT/EP1992/000841 patent/WO1992020179A1/en not_active Application Discontinuation
- 1992-04-14 EP EP92908599A patent/EP0589895A1/en not_active Ceased
- 1992-04-14 AU AU16430/92A patent/AU652052B2/en not_active Withdrawn - After Issue
- 1992-04-14 JP JP4507989A patent/JPH06507053A/en active Pending
- 1992-04-14 CA CA002109211A patent/CA2109211A1/en not_active Abandoned
-
1993
- 1993-11-01 FI FI934830A patent/FI934830A0/en not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
EP0589895A1 (en) | 1994-04-06 |
DE4114274A1 (en) | 1992-11-05 |
CA2109211A1 (en) | 1992-11-03 |
AU1643092A (en) | 1992-12-21 |
WO1992020179A1 (en) | 1992-11-12 |
FI934830A (en) | 1993-11-01 |
FI934830A0 (en) | 1993-11-01 |
AU652052B2 (en) | 1994-08-11 |
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