JPH0630069A - Qam transmission system by multi-subcarrier - Google Patents
Qam transmission system by multi-subcarrierInfo
- Publication number
- JPH0630069A JPH0630069A JP4184869A JP18486992A JPH0630069A JP H0630069 A JPH0630069 A JP H0630069A JP 4184869 A JP4184869 A JP 4184869A JP 18486992 A JP18486992 A JP 18486992A JP H0630069 A JPH0630069 A JP H0630069A
- Authority
- JP
- Japan
- Prior art keywords
- subcarriers
- symbol
- subcarrier
- vector
- information
- 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.)
- Withdrawn
Links
Landscapes
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、マルチサブキャリアに
よるQAM伝送方式に関し、周波数選択性フェージング
があっても高信頼性の多重無線回線を確保できるマルチ
サブキャリアによるQAM伝送方式に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-subcarrier QAM transmission system, and more particularly to a multi-subcarrier QAM transmission system capable of securing a highly reliable multiplex radio line even with frequency selective fading.
【0002】[0002]
【従来の技術】一般に移動体多重無線通信システムは図
2に示すように、複数個のサブキャリア信号の周波数f
1,f2…fmを立て、周波数多重信号を送信してい
る。また、個別のサブキャリアは時分割多重信号により
変調され、あるパワースペクトラムを有する周波数分布
をもってサブキャリアが配列されている。2. Description of the Related Art Generally, a mobile multiplex radio communication system, as shown in FIG. 2, has a frequency f of a plurality of subcarrier signals.
1, f2 ... fm are set and the frequency-multiplexed signal is transmitted. Also, individual subcarriers are modulated by time division multiplexed signals, and the subcarriers are arranged with a frequency distribution having a certain power spectrum.
【0003】従来、この種のマルチサブキャリアに時分
割多重するQAM多重変調方式を適用した場合に、16
QAM変調信号の各信号配置は図3(a)に示すよう
に、表される。すなわち、最大振幅信号点S6,S8,
Sa,S2、第2振幅の信号点S1,S4,Sc,S
9,Sb,Sf,S6,S3、第3振幅の信号点は最大
振幅信号点の位相と同一のS5,Sd,Sc,S7が配
置される。今、各サブキャリア1〜mのそれぞれに対し
て前述の図3(a)に示す信号点を時分割多重した場合
にはシンボルS0〜S9,Sa〜Sfが図4に示す多重
信号配列となる。このシンボル配列はまず同期ワードお
よびパイロットとして最大振幅信号点が配列され、次に
情報データが互いに干渉の少ない振幅と位相配列になる
ように選択される。Conventionally, when a QAM multiplex modulation system in which time division multiplexing is applied to this type of multi-subcarrier is applied, 16
Each signal arrangement of the QAM modulated signal is represented as shown in FIG. That is, the maximum amplitude signal points S6, S8,
Sa, S2, signal points S1, S4, Sc, S of the second amplitude
9, Sb, Sf, S6, S3, and S5, Sd, Sc, S7 having the same phase as the maximum amplitude signal point are arranged as the signal points of the third amplitude. Now, when the signal points shown in FIG. 3A are time-division-multiplexed with respect to each of the subcarriers 1 to m, the symbols S0 to S9 and Sa to Sf become the multiplexed signal arrangement shown in FIG. . This symbol arrangement is first arranged so that the maximum amplitude signal points are arranged as synchronization words and pilots, and then the information data is selected so as to form an amplitude and phase arrangement with less interference with each other.
【0004】このような信号点配列により各サブキャリ
ア信号が変調されるので、同期ワード,パイロットの最
大振幅信号点のある時点におけるパワースペクトラム分
布が各サブキャリアともにパワースペクトラムが集中し
て大きくなり、情報データの領域におけるパワースペク
トラム分布は比較的小さい。なお、ここでサブキャリア
mも他のサブキャリア1,2,3と同様に情報データを
伝送している。これらのデジタル変調方式の伝送誤り訂
正は、情報ビットを予め決められた法則に従い符号化し
て送出し、受信側で復号する方式が用いられている。こ
の時、受信した複数の情報ビットが明らかに正しいと判
断できれば、より高精度の誤り訂正ができる符号方式
(例えば、リード ソロモン符号)があるので、信号受
信レベルで情報ビットの誤り判定をしようとする伝送方
式がある。Since each subcarrier signal is modulated by such a signal point arrangement, the power spectrum distribution at a certain point of the maximum amplitude signal points of the synchronization word and pilot becomes large because the power spectrum is concentrated on each subcarrier. The power spectrum distribution in the area of information data is relatively small. Here, the subcarrier m also transmits information data like the other subcarriers 1, 2, and 3. For transmission error correction of these digital modulation methods, a method is used in which information bits are encoded and transmitted according to a predetermined rule and then decoded on the receiving side. At this time, if it is possible to judge that the received multiple information bits are clearly correct, there is a coding method that enables more accurate error correction (for example, Reed-Solomon code). There is a transmission method to do.
【0005】また、複数サブキャリア方式の伝送方式の
場合も、複数サブキャリアの情報シンボルが同一の信号
空間に集中すると、デジタル信号のパワースペクトラム
が拡大してしまい、高出力のピークパワーを持つ送信機
が必要であった。QAMの場合、デジタル信号の振幅直
線性の精度を要求されるので平均パワーとピークパワー
の差が大きい送信機は、技術的に高度、価格的に高価、
かつ、電力効率の悪化等の問題がある。Also in the case of a transmission system of a plurality of subcarriers, if the information symbols of a plurality of subcarriers are concentrated in the same signal space, the power spectrum of the digital signal is widened, and transmission with a high output peak power is performed. I needed a machine. In the case of QAM, the accuracy of the linearity of the amplitude of the digital signal is required, so a transmitter with a large difference between the average power and the peak power is technically sophisticated and expensive in price.
In addition, there are problems such as deterioration of power efficiency.
【0006】[0006]
【発明が解決しようとする課題】上述した従来のマルチ
サブキャリアによるQAM伝送方式におけるデジタル変
調信号の伝送誤り訂正方式において、信号受信レベルを
入力し、情報シンボルの誤り判定を行なうには、信号受
信レベルと伝送されている情報シンボルの対応を正確に
取らなければならない。信号受信レベルの検出回路は、
通常、半導体とコンデンサ等を組み合わせたものとなり
遅延時間が発生する。一方、情報シンボルの伝送時間
は、伝送スピードの高速化とともに短くなり、信号受信
レベルの遅延時間が無視できなくなり、高精度誤り訂正
の採用を困難にしている。In the transmission error correction method of the digital modulation signal in the above-mentioned conventional QAM transmission method using multi-subcarriers, the signal reception level is input and the error determination of the information symbol is made by the signal reception. The correspondence between the level and the transmitted information symbol must be taken exactly. The signal reception level detection circuit
Normally, a semiconductor and a capacitor are combined to cause a delay time. On the other hand, the transmission time of the information symbol becomes shorter as the transmission speed becomes faster, and the delay time of the signal reception level cannot be ignored, which makes it difficult to adopt high precision error correction.
【0007】また、マルチサブキャリアQAM方式の特
徴であるサブキャリア毎にシンボルベクトルを持ち、そ
の合成ベクトルでデジタル信号のパワースペクトラムが
決定されるため、複数サブキャリアの情報シンボルが近
傍の情報シンボルに集中することで発生することによる
パワースペクトラムの拡大に対応するために電力効率の
悪い、高度・高価な送信機を使用しなければならない欠
点がある。Further, since a symbol vector is provided for each subcarrier, which is a characteristic of the multi-subcarrier QAM system, and the power spectrum of the digital signal is determined by the combined vector, the information symbols of a plurality of subcarriers become neighboring information symbols. There is a drawback in that an advanced and expensive transmitter with low power efficiency must be used in order to cope with the expansion of the power spectrum caused by the concentration.
【0008】[0008]
【課題を解決するための手段】本発明のマルチサブキャ
リアによるQAM伝送方式は周波数がサブキャリアの占
有帯域だけ異なる複数のサブキャリアを別々にQAM変
調した後に周波数多重するマルチサブキャリアによるQ
AM伝送方式において、複数サブキャリアの中の1個又
は複数のサブキャリアをパワー制御用及び誤り検出用の
制御シンボルを伝送する専用サブキャリアとし、情報伝
送する他の複数のサブキャリアの情報シンボルを送出順
毎にベクトル合成して、合成されたベクトルと前記専用
サブキャリアのベクトルとが反対のベクトルとなるが又
は最も近いベクトル情報シンボルの組合せとなるように
送出する。In the QAM transmission method using multi-subcarriers according to the present invention, a plurality of subcarriers whose frequencies differ by the occupied band of the subcarriers are QAM-modulated separately, and then frequency-multiplexed Q is used.
In the AM transmission system, one or a plurality of subcarriers among a plurality of subcarriers is used as a dedicated subcarrier for transmitting control symbols for power control and error detection, and information symbols of other plurality of subcarriers for transmitting information are used. Vectors are combined for each transmission order, and the combined vector and the vector of the dedicated subcarrier are opposite to each other, or are transmitted so that they are the closest combination of vector information symbols.
【0009】[0009]
【実施例】次に図面を参照して本発明を説明する。図1
は本発明の一実施例の通信スロットの構成図を示し、図
3(a)の16QAMの信号点のシンボルに対応してい
る。図3(b)は本実施例の動作原理を説明する合成ベ
クトル図である。The present invention will be described below with reference to the drawings. Figure 1
Shows a configuration diagram of a communication slot according to an embodiment of the present invention, and corresponds to a symbol of a signal point of 16QAM in FIG. FIG. 3B is a combined vector diagram for explaining the operation principle of this embodiment.
【0010】次に図1,図3(b)により本実施例の動
作を説明する。ここでサブキャリア1〜3は情報データ
を送っているが、サブキャリアmは後述するサブキャリ
ア1〜3のパワーの合成ベクトルを打消すために、専用
サブキャリアとして使用される。今サブキャリア1〜3
の合成ベクトルとサブキャリアmの打消すシンボルの位
置により3種類の送信パターンを説明する。対象とする
シンボルのタイムスロットは図1の同期ワードの最初の
1列の例にとる。図3(b)において、 (1)情報シンボルの合成が信号空間に一致する場合の
送信 サブキャリア1の同期ワードの最初のシンバル(S0)
とサブキャリア2の同期ワードの最初のシンボル(S
8)を合成すると、Q軸上に合成シンボル(S0+S
8)が得られる。次にサブキャリア3の同期ワードの最
初のシンボル(Sa)と合成シンボル(S0+S8)を
合成すると、3シンボルの合成(S0+S8+Sa)は
情報シンボル(S8)と等しい信号空間となる。したが
って、送信側でサブキャリアmに挿入するシンボルはシ
ンボル(S8)と信号空間的に対称のシンボル(S2)
とする。この場合は、全てのサブキャリアのシンボル合
成が「0」となるので、パワースペクトラムは最小とな
る。Next, the operation of this embodiment will be described with reference to FIGS. 1 and 3B. Here, the subcarriers 1 to 3 send information data, but the subcarrier m is used as a dedicated subcarrier in order to cancel a combined vector of powers of the subcarriers 1 to 3 described later. Now subcarriers 1-3
The three types of transmission patterns will be described with reference to the combined vector of 1 and the position of the symbol to be canceled by the subcarrier m. The time slot of the symbol of interest is taken as an example of the first column of sync words in FIG. In FIG. 3B, (1) The first cymbal (S0) of the synchronization word of the transmission subcarrier 1 when the combination of information symbols matches the signal space
And the first symbol (S
8), the combined symbol (S0 + S
8) is obtained. Next, when the first symbol (Sa) of the synchronization word of subcarrier 3 and the combined symbol (S0 + S8) are combined, the combined three symbols (S0 + S8 + Sa) becomes a signal space equal to the information symbol (S8). Therefore, the symbol to be inserted into the subcarrier m on the transmission side is a symbol (S2) that is signal-space symmetric to the symbol (S8).
And In this case, the symbol combination of all the subcarriers is “0”, and the power spectrum is the minimum.
【0011】(2)情報シンボルの合成が信号空間に一
致しない場合の送信 図示しないがサブキャリア1の情報シンボル(S4)と
サブキャリア2の情報シンボル(Sc)を合成するとQ
軸上に合成シンボル(S4+Sc)が得られる。次にサ
ブキャリア3の情報シンボル(Se)と合成シンボル
(S4+Sc)を合成すると、3シンボルの合成シンボ
ル(S4+Sc+Se)は一般的な情報シンボルの信号
空間と一致しない。(2) Transmission when information symbol combination does not match the signal space Although not shown, when the information symbol (S4) of subcarrier 1 and the information symbol (Sc) of subcarrier 2 are combined, Q is obtained.
A composite symbol (S4 + Sc) is obtained on the axis. Next, when the information symbol (Se) of the subcarrier 3 and the combined symbol (S4 + Sc) are combined, the combined symbol (S4 + Sc + Se) of 3 symbols does not match the signal space of a general information symbol.
【0012】この場合は、送信側でサブキャリアmに挿
入するシンボルを合成シンボルと信号空間的に対称なシ
ンボル(−(S4+Sc+Se))に一番近いシンボル
(S6)とする。したがって、この時は、全てのサブキ
ャリアのシンボル合成が「0」にならないので、パワー
スペクトラムは最小となららい。In this case, the symbol to be inserted into the subcarrier m on the transmitting side is the symbol (S6) closest to the symbol (-(S4 + Sc + Se)) which is signal spatially symmetric with the combined symbol. Therefore, at this time, the symbol combination of all subcarriers does not become "0", so the power spectrum is not the minimum.
【0013】(3)受信側での情報シンボル誤り検出 受信側では受信したサブキャリア1〜3の情報シンボル
(S0,S8,Sa又はS4,Sc,Se)を送信側と
同じくシンボル合成を行い、合成シンボルと信号空間的
に対称のシンボル(−(S0+S8+Sa)又は−(S
4+Sc+Se))に一番近い情報シンボル(S2又は
S6)とパワー制御用のサブキャリアmで受信した受信
シンボル(S2又はS6)が一致した時、受信した全サ
ブキャリアの各情報シンボルが正しいと判定する。も
し、シンボルが一致しないときは、サブキャリアの情報
シンボルに誤りがあると判定し、再送等の手段により正
しいデータ通信を実現できる。(3) Information symbol error detection on the receiving side On the receiving side, the received information symbols (S0, S8, Sa or S4, Sc, Se) of subcarriers 1 to 3 are symbol-combined in the same manner as the transmitting side, A symbol (-(S0 + S8 + Sa)) or-(S
4 + Sc + Se)) closest to the information symbol (S2 or S6) and the received symbol (S2 or S6) received by the power control subcarrier m, it is determined that each information symbol of all the received subcarriers is correct. To do. If the symbols do not match, it is determined that the information symbol of the subcarrier has an error, and correct data communication can be realized by means of retransmission or the like.
【0014】[0014]
【発明の効果】以上説明したように本発明は、専用サブ
キャリアのシンボルが他のシンボルのサブキャリアの合
成ベクトルと逆のベクトルに配列して比較しているの
で、高精度の誤り訂正が可能となり、伝送誤りの少ない
高効率のデータ通信が可能となる効果がある。また、複
数サブキャリアの情報シンボルがベクトル分散できるの
で、ピークパワーが小さくなり、電力効率の良い経済性
の高いデジタル伝送方式が可能になる効果がある。As described above, according to the present invention, the symbols of the dedicated subcarriers are arranged in the vector opposite to the composite vector of the subcarriers of other symbols for comparison, and therefore highly accurate error correction is possible. Therefore, there is an effect that it is possible to perform highly efficient data communication with few transmission errors. Moreover, since the information symbols of a plurality of subcarriers can be vector-distributed, the peak power is reduced, and there is an effect that a digital transmission method with high power efficiency and high economical efficiency can be realized.
【図1】本発明の一実施例の通信スロットの構成図であ
る。FIG. 1 is a configuration diagram of a communication slot according to an embodiment of the present invention.
【図2】本実施例および従来例に共通のサブキャリアの
周波数配置図である。FIG. 2 is a frequency allocation diagram of subcarriers common to this embodiment and a conventional example.
【図3】本実施例のQAM信号点配置図(a)、および
ベクトル合成図(b)である。FIG. 3 is a QAM signal point constellation diagram (a) and a vector composition diagram (b) of the present embodiment.
【図4】従来の通信スロットの構成図である。FIG. 4 is a configuration diagram of a conventional communication slot.
1,2,3,4 サブキャリア S0〜S9,Sa〜Sf QAM信号点シンボル 1, 2, 3, 4 subcarriers S0 to S9, Sa to Sf QAM signal point symbols
Claims (2)
なる複数のサブキャリアを別々にQAM変調した後に周
波数多重するマルチサブキャリアによるQAM伝送方式
において、複数サブキャリアの中の1個又は複数のサブ
キャリアをパワー制御用及び誤り検出用の制御シンボル
を伝送する専用サブキャリアとし、情報伝送する他の複
数のサブキャリアの情報シンボルを送出順毎にベクトル
合成して、合成されたベクトルと前記専用サブキャリア
のベクトルとが反対のベクトルとなるが又は最も近いベ
クトル情報シンボルの組合せとなるように送出すること
を特徴とするマルチサブキャリアによるQAM伝送方
式。1. In a QAM transmission system using multiple subcarriers, wherein a plurality of subcarriers whose frequencies are different only in an occupied band of the subcarriers are QAM-modulated separately and then frequency-multiplexed, one or a plurality of subcarriers among the plurality of subcarriers. Is used as a dedicated subcarrier for transmitting control symbols for power control and error detection, and information symbols of a plurality of other subcarriers for transmitting information are vector-combined in each transmission order, and the combined vector and the dedicated subcarrier are The QAM transmission method using multi-subcarriers is characterized in that the vector is transmitted in such a manner that the vector is the opposite vector or is the combination of the closest vector information symbols.
ャリアと前記専用サブキャリアとを受信し、受信機で専
用サブキャリアに挿入された制御シンボルと他のサブキ
ャリアに挿入された情報シンボルの合成ベクトルから、
受信した情報シンボルの伝送誤りの有無を検出して、高
精度誤り訂正を行なう手段を有することを特徴とする請
求項1記載のマルチサブキャリアによるQAM伝送方
式。2. A control symbol inserted into a dedicated subcarrier and an information symbol inserted into another subcarrier at a receiver, which receives the plurality of subcarriers and the dedicated subcarrier sent from a transmitter side. From the composite vector of
2. The QAM transmission system with multi-subcarriers according to claim 1, further comprising means for detecting the presence or absence of a transmission error in the received information symbol and performing high precision error correction.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4184869A JPH0630069A (en) | 1992-07-13 | 1992-07-13 | Qam transmission system by multi-subcarrier |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4184869A JPH0630069A (en) | 1992-07-13 | 1992-07-13 | Qam transmission system by multi-subcarrier |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0630069A true JPH0630069A (en) | 1994-02-04 |
Family
ID=16160739
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4184869A Withdrawn JPH0630069A (en) | 1992-07-13 | 1992-07-13 | Qam transmission system by multi-subcarrier |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0630069A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6813317B2 (en) | 1999-12-14 | 2004-11-02 | Matsushita Electric Industrial Co., Ltd. | Multicarrier transmitting method and multicarrier transmitter circuit |
US7006429B2 (en) | 1999-09-30 | 2006-02-28 | Fujitsu Limited | Transmitter, receiver and transmitting method in multi-carrier transmission system |
WO2009040879A1 (en) | 2007-09-25 | 2009-04-02 | Fujitsu Limited | Information processor and control method |
DE112008001528T5 (en) | 2007-06-11 | 2010-04-29 | Toyota Jidosha Kabushiki Kaisha, Toyota-shi | Multiprocessor system and control method therefor |
JP2014532352A (en) * | 2011-10-01 | 2014-12-04 | インテル コーポレイション | Data encoding apparatus and method based on difference of complex amplitude |
-
1992
- 1992-07-13 JP JP4184869A patent/JPH0630069A/en not_active Withdrawn
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7006429B2 (en) | 1999-09-30 | 2006-02-28 | Fujitsu Limited | Transmitter, receiver and transmitting method in multi-carrier transmission system |
US6813317B2 (en) | 1999-12-14 | 2004-11-02 | Matsushita Electric Industrial Co., Ltd. | Multicarrier transmitting method and multicarrier transmitter circuit |
DE112008001528T5 (en) | 2007-06-11 | 2010-04-29 | Toyota Jidosha Kabushiki Kaisha, Toyota-shi | Multiprocessor system and control method therefor |
US8090982B2 (en) | 2007-06-11 | 2012-01-03 | Toyota Jidosha Kabushiki Kaisha | Multiprocessor system enabling controlling with specific processor under abnormal operation and control method thereof |
WO2009040879A1 (en) | 2007-09-25 | 2009-04-02 | Fujitsu Limited | Information processor and control method |
US8181064B2 (en) | 2007-09-25 | 2012-05-15 | Fujitsu Limited | Information processing apparatus for inhibiting instructions, saving and restoring internal information in response to abnormality in redundant processor system |
JP2014532352A (en) * | 2011-10-01 | 2014-12-04 | インテル コーポレイション | Data encoding apparatus and method based on difference of complex amplitude |
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