JP4135579B2

JP4135579B2 - Multilevel modulation method and multilevel demodulation method and apparatus

Info

Publication number: JP4135579B2
Application number: JP2003187573A
Authority: JP
Inventors: 誠一野田
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2003-06-30
Filing date: 2003-06-30
Publication date: 2008-08-20
Anticipated expiration: 2023-06-30
Also published as: JP2005026806A

Description

【０００１】
【発明の属する技術分野】
本発明は、多値変調方法及び多値復調方法と装置に関する。
【０００２】
【従来の技術】
多値変調は、特に、デジタルマイクロ波通信等で用いられており、従来の多値変調技術においては、４ＱＡＭ、16ＱＡＭ、32ＱＡＭ、64ＱＡＭ、128ＱＡＭ、256ＱＡＭ、・・・等の２^ｎＱＡＭが用いられてきた。
【０００３】
このような、デジタルマイクロ波通信等では、一般的に回路の簡便さから、４ＱＡＭ、16ＱＡＭ、32ＱＡＭ、64ＱＡＭ、128ＱＡＭ、256ＱＡＭ、・・・等用いられてきたが、近年の集積回路技術の進歩により、回路の複雑さによる実現の困難さは軽減されつつある。更に、周波数の有効利用、送信電力の有効利用に対する要求が強くなりつつある。
【０００４】
この要請に応えるために、例えば、一般的な二又は二以上の数の変調シンボルに入力データ列を割り当てる構成が提案されている（例えば下記特許文献１参照）。下記特開平０４−１９６９４５号公報には、Ｍ及びＮを２に等しいか又は２よりも大きい整数とし、Ｐを１に等しいか又は１よりも大きくＮ未満の整数とし、Ｑを１に等しいか又は１よりも大きい整数とし、入力の単一又は複数の２値データ列をＭ×Ｎ＋Ｐ列に変換し、Ｎ個の値Ａ_１、Ａ_２、…Ａ_Ｎをそれぞれ２^Ｍ＋ ^Ｐ／Ｎにほぼ等しく、Ａ_１からＡ_Ｎまでの積が２^{Ｍ×Ｎ＋Ｐ}に等しいとして、Ｍ×Ｎ＋Ｐ列の２値データ列を、それぞれ値Ａ_１〜Ａ_Ｎに対応するＭ＋Ｑ列のＮ組の２値データ列の組合せで表現するように変換し、これらＮ組のそれぞれＭ＋Ｑ列の２値データ列を、１組のＭ＋Ｑ列の２値データ列に変換し、１組のＭ＋Ｑ列の２値データ列を入力しそれぞれの時刻で値Ａ_１〜Ａ_Ｎに対応する個数の信号点を位相面上に配置して多値変調する方法（同公報の実施例には、Ｎ＝２、Ｍ＝４、Ｐ＝１、Ｑ＝１、Ａ_１＝２４、Ａ_２＝２４）が開示されている。
【０００５】
下記特許文献１に記載された手法は、一般的な構成を示しているだけであり、入力信号列をｎ個位相面（変調シンボル）に割り当てる場合の具体的な構成法を示しているわけではない。
【０００６】
また、一位相面(Symbol)当たりｐ+1/2ビットの伝送を実現している方法も知られている（特許文献２参照）。すなわち２ｐ＋１列の入力データ信号を２つのｐ＋１列の信号に変換して位相平面上に割り当て、この２つの位相平面を一組として多重し、多値変調して送信し、このとき１組をなす２つの位相平面上の座標の割り当てに所定の関係を持たせることで１つのシンボルに対してｐ＋０．５ビットが割り当てられる構成を実現している。
【０００７】
【特許文献１】
特開平０４−１９６９４５号公報（第２頁、第１図）
【特許文献２】
特開２００３−６０７２４号公報（第３−４頁、第１−５図）
【０００８】
【発明が解決しようとする課題】
本発明の目的は、多値数を２^{（ｐ＋ｑ／ｎ）}値とする変調方法及び復調方法と装置を提供することにある。
【０００９】
また、本発明の他の目的は、シンボル誤り率ＳＥＲ（Symbol Error Rate）を向上させる変調方法及び復調方法を提供することにある。
【００１０】
【課題を解決するための手段】
前記目的を達成する本発明は、
使用する位相面の数ｎを２以上の整数、
ｐを予め定められた所定の自然数、
Ｐを２^ｐである自然数、
ｑを０＜ｑ＜ｎである予め定められた所定の自然数、
Ｑを２^ｑ ^/ ^ｎにほぼ等しく超える数でＰｘＱを自然数とする数として、１つの位相面では、多くてもＰｘＱに等しい自然数の個数の信号点を有し、
ｎ個の位相面全体で、２^{（ｎｘｐ＋ｑ）}個の信号を伝送する変調方法であって、
各々の位相面上で、ＰｘＱ個の信号点を、Ｐ個の２^ｐに等しい信号点（「内部信号点」という）と、（ＰｘＱ−Ｐ）個の２^ｐ ⁺ ^ｑ ^/ ^ｎ−２^ｐにほぼ等しい信号点（「外部信号点」）とに分けるステップと、
ｎ個の全ての位相面で、前記内部信号点のみを用いる場合と、
ｎ個の位相面のうちｉ個（ただし、１＝＜ｉ＜ｎ）の位相面で前記外部信号点を用い、残りの（ｎ−ｉ）個の位相面で前記内部信号点を用いる場合と、を分けて、ｎ個の位相面の全体として、２^{（ｎｘｐ＋ｑ）}種類の信号点を伝送するステップと、
を含む。
【００１１】
【発明の実施の形態】
本発明の実施の形態について説明する。本発明は、ｎを２以上の整数（使用する位相面の数）、ｐを予め定められた所定の自然数、Ｐを２^ｐである自然数、ｑを０＜ｑ＜ｎである予め定められた所定の自然数、Ｑを２^ｑ ^/ ^ｎにほぼ等しく超える数でＰｘＱを自然数とする数として、１つの位相面では、多くてもＰｘＱに等しい自然数個の信号点を有し、ｎ個の位相面全体では、２^{（ｎｘｐ＋ｑ）}個の信号を伝送する変調方法において、各々の位相面上で、ＰｘＱ個の信号点を、Ｐ個の２^ｐに等しい信号点と、（ＰｘＱ−Ｐ）個の２^ｐ ⁺ ^ｑ ^/ ^ｎ−２^ｐにほぼ等しい信号点に分け（前者を「内部信号点」と呼び、後者を「外部信号点」と呼ぶ）、ｎ個の全ての位相面で内部信号点のみを用いる場合と１個以上ｎ個以下の位相面でのみ外部信号点を用い、残りの位相面では内部信号点を用いる場合を分けて、ｎ個の位相面の全体としては、２^{（ｎｘｐ＋ｑ）}種類の信号点を伝送する。多値数は、２^{（ｐ＋ｑ／ｎ）}となる。
【００１２】
本発明の実施形態によれば、ｎ＝４、ｐ≧２、ｑ＝１、Ｑを２^１ ^/ ^４にほぼ等しく超える数で、ＰｘＱ＝５ｘ２⁽ ^ｐ ^-2)である自然数として、４個(ｎ＝４)の位相面上で、ＰｘＱ＝５ｘ２⁽ ^ｐ ^-2)個の信号点を、４個の全ての位相面で２^ｐ個の内部信号点を用いる第１の場合と、４個の位相面の１個を順次選択して、その位相面でのみで２⁽ ^ｐ ^-2)個の外部信号点を用い、残りの３個の位相面では内部信号点を用いる第２の場合を分けて、全体としては、２^{（４ｘｐ＋１）}個の信号点を伝送する。
【００１３】
なお、全て内部信号点の場合には、（２^ｐ）^ｎ＝２^４ｐ個の信号点を伝送することができる。また、１個の位相面の選択は４種類あり、外部信号点数は２⁽ ^ｐ ^-2)個であるので、伝送可能な信号点の数は、４ｘ２⁽ ^ｐ ^-2)ｘ（２^ｐ）^ｎ−１＝２^４ｐ個の信号点を伝送することができる。全体としては、４個(ｎ＝４)の位相面上で、２^４ｐ ⁺ ^１種類の信号点を伝送している。
【００１４】
つまり、
２^４ｘｐ+２^４ｘｐ＝２^（４ｘｐ ⁺ ^１）
である。
【００１５】
本発明の実施形態によれば、ｎ＝３、ｐ≧３、ｑ＝１、Ｑを２^１ ^/ ^３にほぼ等しく超える数で、ＰｘＱ＝１１ｘ２⁽ ^ｐ ^- ^３ ⁾である自然数として、３個(ｎ＝３)の位相面上で、ＰｘＱ＝１１ｘ２⁽ ^ｐ ^- ^３ ⁾個の信号点を、３個の全ての位相面で２^ｐ個の内部信号点を用いる第１の場合と、３個の位相面の１個を順次選択して、１個の位相面でのみで２ｘ２⁽ ^ｐ ^- ^３ ⁾個の外部信号点を用い、残りの２個の位相面では６ｘ２⁽ ^ｐ ^- ^３ ⁾個及び８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いる第２の場合と、３個の位相面の２個を順次選択して、２個の位相面でのみで３ｘ２⁽ ^ｐ ^- ^３ ⁾個の外部信号点を用い、残りの１個の位相面では、８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いる第３の場合と、３個の全ての位相面で２ｘ２⁽ ^ｐ ^- ^３ ⁾個の外部信号点を用いる第４の場合を分けて、全体としては２^{（３ｘｐ＋１）}種類の信号点を伝送する。
【００１６】
なお、第１の場合として、全て内部信号点の場合には、
（２^ｐ）^ｎ＝２^３ｐ個の信号点を伝送することができる。
【００１７】
また、第２の場合として、１個の位相面の選択は、３種類（_３C_１＝３）あり、３ｘ２⁽ ^ｐ ^- ^３ ⁾個ある外部信号点の内の２ｘ２⁽ ^ｐ ^- ^３ ⁾個を外部信号点として用い、２つの位相面における内部信号点としては、６ｘ２⁽ ^ｐ ^- ^３ ⁾個、及び８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いることによって、
３ｘ（２ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（６ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）
＝９ｘ２^{（３ｘｐ−４）}
個の信号点を伝送することができる。
【００１８】
第３の場合として、２個の位相面の選択は３種類（_３C_２＝３）あり、３ｘ２⁽ ^ｐ ^- ^３ ⁾個ある外部信号点の内の３ｘ２⁽ ^ｐ ^- ^３ ⁾個を外部信号点として用い１つの位相面において内部信号点としては、８ｘ２⁽ ^ｐ ^- ^３ ⁾個の信号点を用いることによって、
３ｘ（３ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（３ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）
＝２７ｘ２^{（３ｘｐ−６）}
個の信号点を伝送することができる。
【００１９】
第４の場合として、３個の位相面の選択は１種類（_３C_３＝１）あり、３ｘ２⁽ ^ｐ ^- ^３ ⁾個ある外部信号点の内の２ｘ２⁽ ^ｐ ^- ^３ ⁾個を外部信号点として全ての位相面で用いることによって、
１ｘ（２ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（２ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（２ｘ２⁽ ^ｐ ^- ^３ ⁾）
＝２^{（３ｘｐ−６）}
個の信号点を伝送することができる。
【００２０】
全体としては、３個(ｎ＝３)の位相面上で、２^３ｘｐ ⁺ ^１個の信号点を伝送している。
【００２１】
つまり、
２^３ｘｐ+９ｘ２^{（３ｘｐ−４）}+２７ｘ２^{（３ｘｐ−６）}+２^{（３ｘｐ−６）}
＝２^３ｘｐ ⁺ ^１
である。
【００２２】
本発明の実施の形態によれば、ｎ＝２、ｐ≧１、ｑ＝１、Ｑを２^１ ^/ ^２にほぼ等しく超える数で、ＰｘＱ＝３ｘ２^{（ｐ−１）}である自然数として、２個(ｎ＝２)の位相面上で、ＰｘＱ＝３ｘ２^{（ｐ−１）}個の信号点を、２個の全ての位相面で２^ｐ個の内部信号点を用いる第１の場合と、２個の位相面の１個を順次選択して、１個の位相面でのみで１ｘ２^{（ｐ−１）}個の外部信号点を用い、残りの１個の位相面では２ｘ２^{（ｐ−１）}個の内部信号点を用いる第２の場合とを分けて、全体としては２^{（２ｘｐ＋１）}種類の信号点を伝送する。
【００２３】
なお、第１の場合として、全て内部信号点の場合には、（２^ｐ）^ｎ＝２^２ｐ個の信号点を伝送することができる。
【００２４】
また、第２の場合として、１個の位相面の選択は２種類（_２C_１＝２）あり、１ｘ２^{（ｐ−１）}個ある外部信号点の内の１ｘ２^{（ｐ−１）}個を外部信号点として用い、内部信号点としては、２ｘ２^{（ｐ−１）}個の内部信号点を用いることによって、
２ｘ（１ｘ２^{（ｐ−１）}）ｘ（２ｘ２^{（ｐ−１）}）＝２^{（２ｘｐ）}
個の信号点を伝送することができる。
【００２５】
全体としては、２個(ｎ＝２)の位相面上で、２^（２ｘｐ ⁺ ^１）個の信号点を伝送している。
【００２６】
つまり、
２^２ｐ+２^２ｐ＝２^２ｐ ⁺ ^１
である。
【００２７】
本発明の実施形態によれば、ｎ＝３、ｐ≧２、ｑ＝２、Ｑを２^２ ^/ ^３にほぼ等しく超える数で、ＰｘＱ＝７ｘ２⁽ ^ｐ ^-2)である自然数として、３個(ｎ＝３)の位相面上で、ＰｘＱ＝７ｘ２⁽ ^ｐ ^-2)個の信号点を、３個の全ての位相面で２^ｐ個の内部信号点を用いる第１の場合と、３個の位相面の１個を順次選択して、１個の位相面でのみで３ｘ２⁽ ^ｐ ^-2)個の外部信号点を用い、残りの２個の位相面では、４ｘ２⁽ ^ｐ ^-2)個の内部信号点を用いる第２の場合と、３個の位相面の２個を順次選択して、２個の位相面でのみで３ｘ２⁽ ^ｐ ^-2)個の外部信号点の内の２ｘ２⁽ ^ｐ ^-2)個を用い、残りの１個の位相面では４ｘ２⁽ ^ｐ ^-2)個の内部信号点を用いる第３の場合を分けて、全体としては、２^{（３ｘｐ＋２）}種類の信号点を伝送する。
【００２８】
なお、第１の場合として、全て内部信号点の場合には、（２^ｐ）^ｎ＝２^３ｐ個の信号点を伝送することができる。
【００２９】
また、第２の場合として、１個の位相面の選択は３種類（_３C_１＝３）あり、３ｘ２⁽ ^ｐ ^-2)個ある外部信号点の内の３ｘ２⁽ ^ｐ ^-2)個を外部信号点として用い、２つの位相面における内部信号点としては、４ｘ２⁽ ^ｐ ^-2)個の内部信号点を用いることによって、
３ｘ（３ｘ２⁽ ^ｐ ^-2)）ｘ（４ｘ２⁽ ^ｐ ^-2)）ｘ（４ｘ２⁽ ^ｐ ^-2)）
＝９ｘ２^{（３ｘｐ−２）}
個の信号点を伝送することができる。
【００３０】
第３の場合として、２個の位相面の選択は３種類（_３C_２＝３）あり、３ｘ２⁽ ^ｐ ^- ^３ ⁾個ある外部信号点の内の２ｘ２⁽ ^ｐ ^-2)個を外部信号点として用い、１つの位相面において内部信号点としては、４ｘ２⁽ ^ｐ ^-2)個の信号点を用いることによって、
３ｘ（２ｘ２⁽ ^ｐ ^-2)）ｘ（２ｘ２⁽ ^ｐ ^-2)）ｘ（４ｘ２⁽ ^ｐ ^-2)）
＝３ｘ２^{（３ｘｐ−２）}
個の信号点を伝送することができる。
【００３１】
全体としては、３個(ｎ＝３)の位相面上で、２^{（３ｘｐ−２）}個の信号点を伝送している。
【００３２】
つまり、
２^３ｐ+９ｘ２^{（３ｘｐ−２）}+３ｘ２^{（３ｘｐ−２）}
＝２^３ｘｐ ⁺ ^２
である。
【００３３】
本発明の実施形態によれば、ｎ＝４、ｐ≧３、ｑ＝３、Ｑを２^３ ^/ ^４にほぼ等しく超える数で、ＰｘＱ＝１４ｘ２⁽ ^ｐ ^- ^３ ⁾である自然数として、４個(ｎ＝４)の位相面上で、ＰｘＱ＝１４ｘ２⁽ ^ｐ ^- ^３ ⁾個の信号点を、４個の全ての位相面で２^ｐ個の内部信号点を用いる第１の場合と、４個の位相面の１個を順次選択して、１個の位相面でのみで６ｘ２⁽ ^ｐ ^- ^３ ⁾個の外部信号点を用い、残りの３個の位相面では、８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いる第２の場合と、４個の位相面の２個を順次選択して、２個の位相面でのみで６ｘ２⁽ ^ｐ ^- ^３ ⁾個の外部信号点を用い、残りの２個の位相面では８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いる第３の場合と、４個の位相面の３個を順次選択して、３個の位相面でのみで、４ｘ２⁽ ^ｐ ^- ^３ ⁾個及び４ｘ２⁽ ^ｐ ^- ^３ ⁾個及び５ｘ２⁽ ^ｐ ^- ^３ ⁾個の外部信号点を用い、残りの１個の位相面では８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いる第４の場合を分けて、全体としては２^{（４ｘｐ＋３）}種類の信号点を伝送する。
【００３４】
なお、全て内部信号点の場合には、（２^ｐ）^ｎ＝２^４ｐ個の信号点を伝送することができる。
【００３５】
また、第２の場合として、１個の位相面の選択は４種類（_４Ｃ_１＝４）あり、６ｘ２⁽ ^ｐ ^- ^３ ⁾個ある外部信号点の内の６ｘ２⁽ ^ｐ ^- ^３ ⁾個を外部信号点として用い三つの位相面における内部信号点としては、８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いることによって、
４ｘ（６ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）
＝３ｘ２^４ｘｐ
個の信号点を伝送することができる。
【００３６】
第３の場合として、２個の位相面の選択は６種類（_４Ｃ_２＝６）あり、６ｘ２⁽ ^ｐ ^- ^３ ⁾個ある外部信号点の内の６ｘ２⁽ ^ｐ ^- ^３ ⁾個を外部信号点として用い、２つの位相面において内部信号点としては、８ｘ２⁽ ^ｐ ^- ^３ ⁾個の信号点を用いることによって、
６ｘ（６ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（６ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）
＝27ｘ２^{（４ｘｐ−} ³ ^）
個の信号点を伝送することができる。
【００３７】
第４の場合として、３個の位相面の選択は１種類（_４Ｃ_３＝４）あり、６ｘ２⁽ ^ｐ ^- ^３ ⁾個ある外部信号点の内の４ｘ２⁽ ^ｐ ^- ^３ ⁾個、４ｘ２⁽ ^ｐ ^- ^３ ⁾個及び５ｘ２⁽ ^ｐ ^- ^３ ⁾個を外部信号点として用い、残りの位相面では８ｘ２⁽ ^ｐ ^- ^３ ⁾個の内部信号点を用いることによって、
４ｘ（４ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（４ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（５ｘ２⁽ ^ｐ ^- ^３ ⁾）ｘ（８ｘ２⁽ ^ｐ ^- ^３ ⁾）
＝５ｘ２^{（４ｘｐ−} ³ ^）個の信号点を伝送することができる。
【００３８】
全体としては、４個(ｎ＝４)の位相面上で、２^４ｐ ⁺ ^３個の信号点を伝送している。
【００３９】
つまり、
２^４ｘｐ+３ｘ２^４ｘｐ+27ｘ２^{（４ｘｐ−} ³ ^）+５ｘ２^{（４ｘｐ−３）}
＝２^（４ｘｐ ⁺ ^３）
である。
【００４０】
上記実施形態は、いずれも、ｎ個の位相面で、合計２^{（ｎｐ＋ｑ）}値の信号を伝送しており、１つの位相面では、平均的に２^{（ｐ＋ｑ／ｎ）}値の信号を伝送している。
【００４１】
従って、従来は多値変調においては４ＱＡＭ、１６ＱＡＭ、３２ＱＡＭ、６４ＱＡＭ、１２８ＱＡＭ、２５６ＱＡＭ、…等のｎを任意の正の整数として２^ｎＱＡＭが用いられてきたが、本発明は、多値数を２^{（ｐ＋ｑ／ｎ）}値にすることを可能としている。
【００４２】
その効果として、２^ｐＱＡＭでは周波数帯域に余裕があり過ぎだが、２^{（ｐ−１）}ＱＡＭでは、要求される周波数帯域に入らない場合に、それらの中間の変調方式を提供することができる。その結果、周波数の有効利用が図れると共に、２^ｐＱＡＭに比べて、少ない所用の信号対雑音比で、２^{（ｐ−１）}ＱＡＭが実現できることから、電力の有効利用にもなる。
【００４３】
本発明により、一位相面(Symbol)当たり、ｐ+1/2ビットの伝送を実現した場合には、ｐ＝３の場合について、シンボル誤り率ＳＥＲ（Symbol Error Rate）の点で、約０.１４ｄＢ優れている。
【００４４】
【実施例】
本発明の実施例について図面を参照して説明する。図１は、本発明の第１の実施例として、位相面の数ｎ＝４、ｐ＝４、ｑ＝1、ＰｘＱ＝２０の場合の信号点の伝送を説明するための図である。ｐ≧２のｐとしてｐ＝４、０＜ｑ＜４としてｑ＝１とし、Ｐ＝２^４＝１６、Ｑを５／４としており、ＰｘＱ＝５ｘ２⁽ ^ｐ ^-2)＝２０となる。図１は、変調シンボルのマッピングを示した図であり、多値変調器の出力する第１乃至第４の変調シンボルを、位相平面上のいわゆるコンスタレーション（変調波の信号配置点）として表現した信号図である。図１には、第１乃至第４シンボルのとり得る座標点を黒点にて示している。
【００４５】
４個(ｎ＝４)の位相面上で、ＰｘＱ＝２０個の信号点を、
（Ａ）４個の全ての位相面で１６＝２^４個の内部信号点を用いる第１の場合（２^４ｘ２^４ｘ２^４ｘ２^４）と、
（Ｂ）４個の位相面の１個を順次選択して、その位相面でのみで２⁽ ^ｐ ^-2)＝４個の外部信号点を用い、残りの３個の位相面では内部信号点を用いる第２の場合（４ｘ２^４ｘ２^４ｘ２^４）と、
を分ける。なお、図１において、１６＝２^４点の内部信号点は、１６ＱＡＭ（直交振幅変調）の変調波の信号点配置（マッピング）に相当している。４個の外部信号点は、１６ＱＡＭの信号点配置の外部にある信号点に対応している。
【００４６】
第１の場合（図１（Ａ））は、１通り、
第２の場合（図１（Ｂ））は、外部信号点の位相面の選択の仕方について_４Ｃ_１（＝４通り）となり、
全体としては、
２^４ｘ２^４ｘ２^４ｘ２^４＋４ｘ４ｘ２^４ｘ２^４ｘ２^４＝２ｘ２^４ｘ２^４ｘ２^４ｘ２^４＝２ｘ２^４ｘ２^４ｘ２^４ｘ２^４＝２^{（４ｘ４＋１）}種類の信号点を伝送する。
【００４７】
１個の位相面では、平均的に２^{（４ｘ４＋１）／４}＝２^４．２５値の信号を伝送し、４個の位相面で全体として２^１７値の信号を伝送することができる。
【００４８】
図２は、本発明の第２の実施例として、位相面の数ｎ＝３、ｐ＝４、ｑ＝１、ＰｘＱ＝２２の場合について説明するための図である。
【００４９】
ｐ≧２のｐとして、ｐ＝４、０＜ｑ＜３としてｑ＝１とし、Ｐ＝２^４＝１６、Ｑを１１／８としており、ＰｘＱ＝１１ｘ２⁽ ^ｐ ^- ^３ ⁾＝１１ｘ２＝２２となる。
【００５０】
３個(ｎ＝３)の位相面上で、ＰｘＱ＝２２個の信号点を、
（Ａ）３個の全ての位相面で２^ｐ＝２^４個の内部信号点を用いる第１の場合（２^４ｘ２^４ｘ２^４）と、
（Ｂ）３つの位相面の１つを順次選択して、１つの位相面でのみで、２ｘ２⁽ ^ｐ ^- ^３ ⁾＝２ｘ２個の外部信号点を用い、残りの２つの位相面では６ｘ２⁽ ^ｐ ^- ^３ ⁾＝６ｘ２個、及び８ｘ２⁽ ^ｐ ^- ^３ ⁾＝８ｘ２個の内部信号点を用いる第２の場合と、
（Ｃ）３つの位相面の２つを順次選択して、２つの位相面でのみで、３ｘ２⁽ ^ｐ ^- ^３ ⁾＝３ｘ２＝６個の外部信号点を用い、残りの１つの位相面では８ｘ２⁽ ^ｐ ^- ^３ ⁾＝８ｘ２個の内部信号点を用いる第３の場合と、
（Ｄ）３個の全ての位相面で、２ｘ２⁽ ^ｐ ^- ^３ ⁾＝２ｘ２＝４個の外部信号点を用いる第４の場合と、
を分ける。
【００５１】
第１の場合（図２（Ａ）参照）は、１通り、
第２の場合（図２（Ｂ）参照）は、_３Ｃ_１（＝３通り）となり、
第３の場合（図２（Ｃ）参照）は、_３Ｃ_２＝３通り、
第４の場合（図２（Ｄ）参照）は、_３Ｃ_３＝１通りとなる。
【００５２】
全体としては、
２^４ｘ２^４ｘ２^４＋３ｘ４ｘ（６ｘ２）ｘ（８ｘ２）＋３ｘ６ｘ６ｘ（８ｘ２）＋１ｘ４ｘ４ｘ４
＝４０９６＋２３０４＋１７２８＋６４＝８１９２＝２^{（３ｘ４＋１）}種類の信号点を伝送する。
【００５３】
１個の位相面では、平均的に２^{（３ｘ４＋１）／３}＝２^４．３３値の信号を伝送し、３個の位相面で全体として２^１３値の信号を伝送することができる。
【００５４】
図３は、本発明の第３の実施例として、位相面の数ｎ＝２、ｐ＝４、ｑ＝１、ＰｘＱ＝２４の場合について説明するための図である。Ｐ＝２^４、Ｑを３／２とし、ＰｘＱ＝３ｘ２^{（ｐ−１）}＝３ｘ２^３＝２４とする。
【００５５】
２個(ｎ＝２)の位相面上で、ＰｘＱ＝３ｘ２^３個の信号点を、
（Ａ）２個の全ての位相面で２^４個の内部信号点を用いる第１の場合と、
（Ｂ）２つの位相面の１つを順次選択して、１つの位相面でのみで１ｘ２^３個の外部信号点を用い、残りの１つの位相面では２ｘ２^３個の内部信号点を用いる第２の場合と、を分ける。
【００５６】
第１の場合（図３（Ａ）参照）は、１通りであり、信号点の数は、１６ｘ１６＝２５６、
第２の場合（図３（Ｂ）参照）は、２通り（_２Ｃ_１）であり、信号点の数は２ｘ８ｘ１６＝２５６となり、全体の信号点の数は、
２５６＋２５６＝５１２＝２^９種類の信号点が伝送される。
【００５７】
１個の位相面では平均的に２^９／２＝２^４．５値の信号を伝送し、２個の位相面で全体として、２^９値の信号を伝送することができる。
【００５８】
図４は、本発明の第４の実施例として、ｎ＝３、ｐ＝４、ｑ＝２、ＰｘＱ＝２８の場合を説明するための図である。Ｐ＝２^４、Ｑを７／４とし、ＰｘＱ＝７ｘ２⁽ ^ｐ ^-2)（＝２８）とする。
【００５９】
３個(ｎ＝３)の位相面上で、ＰｘＱ＝２８個の信号点を、
（Ａ）３個の全ての位相面で２^４個の内部信号点を用いる第１の場合と、
（Ｂ）３つの位相面の１個を順次選択して、１つの位相面でのみで３ｘ２^２個の外部信号点を用い、残りの２つの位相面では４ｘ２^２個の内部信号点を用いる第２の場合と、
（Ｃ）３個の位相面の２個を順次選択して、２個の位相面でのみで、３ｘ２^４個の外部信号点の内の２ｘ２^２個を用い、残りの１つの位相面では、４ｘ２^２個の内部信号点を用いる第３の場合と、
を分ける。
【００６０】
第１の場合（図４（Ａ）参照）は、１通り（２^４ｘ２^４ｘ２^４＝４０９６）、
第２の場合（図４（Ｂ）参照）は、３通り（_３Ｃ_１）あり（３ｘ３ｘ２^２ｘ４ｘ２^２ｘ４ｘ２^２＝９２１６）、
第３の場合（図４（Ｃ）参照）は、３通り（_３Ｃ_２）あり（３ｘ２ｘ２^２ｘ２ｘ２^２ｘ４ｘ２^２＝３０７２）、
全体としては、
４０９６＋９２１６＋３０７２＝１６３８４＝２^{（３ｘ４＋２）}種類の信号点を伝送する。
【００６１】
１個の位相面では平均的に、２^{（３ｘ４＋２）／３}＝２^４． ⁶⁷値の信号を伝送し、３個の位相面で全体として２^１４値の信号を伝送することができる。
【００６２】
図５は、本発明の第５の実施例として、ｎ＝４、ｐ＝４、ｑ＝３、ＰｘＱ＝２８の場合について説明するための図である。Ｐ＝２^４、Ｑを７／４とし、ＰｘＱ＝１４ｘ２⁽ ^ｐ ^- ^３ ⁾＝２８とする。
【００６３】
４つ(ｎ＝４)の位相面上で、ＰｘＱ＝１４ｘ２^１＝２８個の信号点を、
（Ａ）４つの全ての位相面で２^４個の内部信号点を用いる第１の場合と、
（Ｂ）４つの位相面の１つを順次選択して、１つの位相面でのみで６ｘ２^１個の外部信号点を用い、残りの３つの位相面では８ｘ２^１個の内部信号点を用いる第２の場合と、
（Ｃ）４つの位相面の２つを順次選択して、２つの位相面でのみで６ｘ２^１個の外部信号点を用い、残りの２つの位相面では８ｘ２^１個の内部信号点を用いる第３の場合と、
（Ｄ）４つの位相面の３つを順次選択して、３つの位相面でのみで４ｘ２^１個及び４ｘ２^１個、及び、５ｘ２^１個の外部信号点を用い、残りの１つの位相面では８ｘ２^１個の内部信号点を用いる第４の場合と、
を分ける。
【００６４】
第１の場合（図５（Ａ）参照）は、２^４ｘ２^４ｘ２^４ｘ２^４＝６５５３６、
第２の場合（図５（Ｂ）参照）は、_４Ｃ_１＝４通りあり、４ｘ（６ｘ２^１）ｘ（８ｘ２^１）ｘ（８ｘ２^１）ｘ（８ｘ２^１）＝１９６６０８、
第３の場合（図５（Ｃ）参照）は、_４Ｃ_２＝６通りあり、６ｘ（６ｘ２^１）ｘ（６ｘ２^１）ｘ（８ｘ２^１）ｘ（８ｘ２^１）＝２２１１８４、
第４の場合（図５（Ｄ）参照）は、_４Ｃ₃＝４通りあり、４ｘ（４ｘ２^１）ｘ（４ｘ２^１）ｘ（５ｘ２^１）ｘ（８ｘ２^１）＝４０９６０、
全体としては、
６５５３６＋１９６６０８＋２２１１８４＋４０９６０＝５２４２８８＝２^１９＝２^{（４ｘ４＋３）}種類の信号点を伝送する。
【００６５】
１個の位相面では平均的に、２^{（４ｘ４＋３）／４}＝２^４．７５値の信号を伝送し、４個の位相面で全体として２^１９値の信号を伝送することができる。
【００６６】
上記特許文献２の一シンボル当りｐ+1/2ビットの伝送では、複数の位相面を用いて１つの位相面では必ずしも２の自然数乗とはならない多値変調を提供しているが、第１の位相面を分割することで場合分けを行い、他の位相面では最大信号点数まで配置している。
【００６７】
本発明は、各々の位相面で、内部信号点と外部信号点を分けて、外部信号点を使用する位相面の組み合わせに一部の情報を載せている。
【００６８】
本発明によれば、信号多値数を２の自然数乗とせず、例えば、１６（＝２^４）と３２（＝２^５）の間の２４を多値数とする多値変調方法を提供する。
【００６９】
本発明は、この２４値変調の場合、２４より小さい最大の２の自然数乗である１６個の信号点を内部信号点とし、それ以外の８（＝２４-１６）個の信号点を外部信号点として、外部信号点の数と位置にも情報を付加する事で、効率的な伝送を実現している。
【００７０】
その結果、ｎ個の位相面で、合計２^{（ｎｘｐ＋ｑ）}値の信号を伝送しており、１つの位相面では平均的に２^{（ｐ＋ｑ／ｎ）}値の信号を伝送している。
【００７１】
その効果として、図６に示す様に、従来技術である２^ｎ値ＱＡＭに比べて、中間の多値伝送を実現できる。
【００７２】
図６に示すように、ＢＰＳＫでは１シンボルに１ビットの情報を伝送し、ＱＰＳＫでは１シンボルに２ビットの情報を伝送し、８ＰＳＫでは１シンボルに３ビットの情報を伝送している。また、２^ｎ値ＱＡＭの伝送効率として、１６ＱＡＭでは、４ビット/シンボル、３２ＱＡＭでは、５ビット/シンボル、６４ＱＡＭでは、６ビット/シンボルとされる。このように、多値伝送方式において、１つの位相面で伝送することができる情報量は、従来技術である２^ｎ値ＱＡＭでは、ｎビット/シンボルという離散的な値であった。本発明により実現される変調では、伝送効率（１シンボルあたり伝送される情報のビット数）は、離散的値の中間値を実現するものである。
【００７３】
また、上記特許文献２に記載されている発明も、一位相面(Symbol)当たりｐ+1/2ビットの伝送を実現しているが、本発明は、シンボル誤り率ＳＥＲ（Symbol Error Rate）の点で、約０．１４ｄＢ優れている。本発明の２４ＱＡＭの総電力は、１１．４６ｄＢ(＝10log14)であるのに対して、上記特許文献２の場合には、１１．６０ｄＢである。
【００７４】
この理由は、本発明では、位相面上の信号点を内部信号点と外部信号点に分割し、外部信号点の数と位置にも情報を付加することで、送信電力を低減する効果が働いているためである。
【００７５】
また、図７、図８に、ｐ＝１〜６における、本発明の具体的なパラメーターを示しておく。
【００７６】
例えば、図７において、ｐ＝４、ｎ＝２、ｑ＝１の場合には、２４ＱＡＭを実現している。外部信号点数が０のときには、２つの位相面でいずれも内部信号点として１６点を選択し、外部信号点数が１のときには、外部信号点を用いる位相面を順次選択し、一方の位相面で外部信号点として８点を用いると同時に、他方の位相面で内部信号点として、１６点を用いる。
【００７７】
２つの位相面で、総計として、（１６ｘ１６）+２ｘ（８ｘ１６）＝５１２種類の二値信号を伝送することができる。５１２＝２^９であり、２つの位相面で２^９値を伝送しているので、１つの位相面では平均的に２^４．５値の信号伝送を行っている。
【００７８】
図９は、本発明の第１の実施形態の多値変調装置（１００）の構成を示すブロック図である。ｎ個の位相面で、合計、２^{（ｎｘｐ＋ｑ）}値の信号を伝送しており，１つの位相面では、平均して、２^{（ｐ＋ｑ／ｎ）}値の信号を伝送している。
【００７９】
位相面の個数ｎ＝４、ｐ≧２、ｑ＝１、Ｑを２^１ ^/ ^４にほぼ等しく超える数で、ＰｘＱ＝５ｘ２⁽ ^ｐ ^-2)である自然数として、４個(ｎ＝４)の位相面上で、ＰｘＱ＝５ｘ２⁽ ^ｐ ^-2)個の信号点を、４個の全ての位相面で２^ｐ個の内部信号点を用いる第１の場合（図１（Ａ）参照）と、４個の位相面の１個を順次選択して、１個の位相面でのみで２⁽ ^ｐ ^-2)個の外部信号点を用い他の３個の位相面では内部信号点を用いる第２の場合（図１（Ｂ）参照）を分けて、全体としては２^{（４ｘｐ＋１）}個の信号点を伝送する。全て内部信号点の場合には、（２^ｐ）^４＝２^４ｐ個の信号点を伝送することができる。また、１個の位相面の選択は４種類あり、外部信号点数は２⁽ ^ｐ ^-2)個であるため、伝送可能な信号点の数は、４ｘ２⁽ ^ｐ ^-2)ｘ（２^ｐ）^ｎ−１＝２^４ｐ個の信号点を伝送することができる。全体としては、４個(ｎ＝４)の位相面上で、２^４ｐ＋２^４ｐ＝２^４ｘｐ ⁺ ^１種類の信号点を伝送している。図９を参照すると、本実施例の多値変調装置１００は、入力端子１と、データ列数変換回路２と、第１のデータ変換回路３と、第２のデータ変換回路４と、並列直列変換回路５と、多値変調器６と、出力端子７とを備えている。以下では、図１に示した多値変調を行う構成を例に説明する。なお、多値変調装置１００の詳細は、例えば上記特許文献２等の記載が参照される。
【００８０】
第１のデータ変換回路３、および第２のデータ変換回路４は、データ列数変換回路２の出力する例えば４ｐ＋１列（ビット幅）の入力データ信号２１を変換する。第１のデータ変換回路３は、入力データ信号２１の値に応じて、ｐ＋１列の信号を出力する。第２のデータ変換回路４は、第１のデータ変換回路３の出力信号を受け、入力データ信号２１の値を参照して、外部信号点を用いる位相面の有無を判定し、外部信号点を用いる位相面の数が０の場合、図１（Ａ）に示すマッピングにしたがって、４つの変換データ信号（第１乃至第４の変調シンボル）４１_１〜４１_ｎ（ｎ＝４）を出力する。また、第２のデータ変換回路４は、第１のデータ変換回路３の出力信号を受け、入力データ信号２１の値を参照して、外部信号点を用いる位相面の数が１の場合、図１（Ｂ）に示すマッピングにしたがって４つの変換データ信号（第１乃至第４の変調シンボル）４１_１〜４１_ｎ（ｎ＝４）を出力する。第１、２のデータ変換回路３、４での変換は、ＲＯＭ（読み出し専用メモリ）等のメモリを参照して変換するテーブルルックアップ法等により行われる。並列直列変換回路５は、第２のデータ変換回路４の出力信号を入力して時分割多重化し、ｐ＋１列の多重化信号５１を出力する。多値変調器６は、多重化信号５１として伝送された変調シンボルに基づき搬送波を多値変調し、出力端子７へ出力する。なお、第１、第２のデータ変換回路３、４を１つの変換回路として構成してもよいことは勿論である。
【００８１】
図１０は、本発明の第１の実施の形態による多値復調装置（２００）の構成を示すブロック図である。図１０を参照すると、本実施の形態の多値復調装置２００は、入力端子１１と、多値復調器１２と、直列並列変換回路１３と、データ逆変換回路１４と、出力端子１５とを備えている。図１０の多値復調装置（２００）は、図９の多値変調装置（１００）から送信された信号を受信して復調するものである。
【００８２】
多値復調器１２は、入力端子１１に入力された通信信号を復調し、例えばｐ＋１列の受信復調データ列信号１２１を出力する。直列並列変換回路１３は、受信復調データ列信号１２１を時分割多重分離して、それぞれｐ＋１列の、ｎ個（ｎ＝４）の復調データ列信号１３１_１〜１３１_ｎを出力する。データ逆変換回路１４は、第１乃至第ｎの復調データ列信号１３１_１〜１３１_ｎを入力し、復調データ列信号１４１を出力する。ここでデータ逆変換回路１４は、例えば第１の復調データ列信号の値に基づき、例えば図１に示したシンボルのマッピングにしたがって、外部信号点を用いていない場合には、第１乃至第４の復調データ列信号としてそれぞれ予め定めた２^４ｐ種の値を示す信号を受けて、第１、第２、第３、第４の復調データ列信号の示す値に基づき予め定めた復調データ値を生成し、この復調データ値を４ｐ＋１列の復調データ信号として出力する。一方、外部信号点を用いる場合、第１乃至第４の復調データ列信号としてそれぞれ予め定めた２^４ｐ種の値を示す信号を受けて、第１、第２、第３、第４の復調データ列信号の示す値に基づき予め定めた復調データ値を生成し、この復調データ値を４ｐ＋１列の復調データ信号として出力する。データ逆変換回路１４における逆変換は、例えばＲＯＭ等によるテーブルルックアップ法により実現される。
【００８３】
図１１は、本発明の一実施例の変調処理を説明するフローチャートである。ステップＳ１で入力データ信号を入力する。ステップＳ２で，入力データ信号に基づき、変調シンボルの信号点配置として、外部信号点を用いるか否か判定する。外部信号点を用いない場合、ステップＳ４で、ｎ個の位相面で内部信号点を用いた場合について第１乃至第ｎの変換データ（変調シンボル）を生成する。一方、外部信号点を用いる場合、ステップＳ３で、ｎ個の位相面のうち所定個数の位相面で外部信号点を用い、残り位相面で内部信号点のみを用いた場合について第１乃至第ｎの変換データ（変調シンボル）を生成する。ステップＳ５でｎ個の変換データ（変調シンボル）を変調器に出力する。
【００８４】
本発明の変調方法で変調された信号を受信し復調する装置では、上記した変調方法の逆過程が行われる。
【００８５】
図１２は、本発明の一実施例の復調処理を説明するフローチャートである。ステップＳ１１で、ｎ個の復調データ列信号を入力し、ステップＳ１２で、第１乃至第ｎの復調データ列信号に基づき、変調シンボルの信号点配置として、外部信号点を用いていない場合、第１乃至第４の復調データ列信号としてそれぞれ予め定めた２^４ｐ種の値を示す信号を受けて、第１乃至第４の復調データ列信号の示す値に基づき予め定めた第１乃至第４の復調データ値を生成し、この復調データ値を４ｐ＋１列の復調データ信号として出力する。変調シンボルの信号点配置として、外部信号点を用いる場合、１個の位相面の選択は４種類あり、外部信号点数は２⁽ ^ｐ ^-2)個であるので４ｘ２⁽ ^ｐ ^-2)ｘ（２^ｐ）^ｎ−１＝２^４ｐ種の値を第１乃至第４の復調データ列信号として受けて、第１乃至第４の復調データ列信号の示す値に基づき予め定めた復調データ値を生成し、この復調データ値を例えば４ｘｐ＋１列の復調データ信号として出力する。
【００８６】
以上本発明を上記実施例に即して説明したが、本発明は、上記実施例の構成にのみ限定されるものでなく、本発明の原理の範囲内で当業者であればなし得るであろう各種変形、修正を含むことは勿論である。
【００８７】
【発明の効果】
以上説明したように、本発明によれば、ｎ個の位相面で合計２^{（ｎｐ＋ｑ）}値の信号を伝送し、１つの位相面では平均的に２^{（ｐ＋ｑ／ｎ）}値の信号を伝送し、多値数を２^{（ｐ＋ｑ／ｎ）}値にすることを可能している。
【００８８】
本発明によれば、２^ｐＱＡＭでは周波数帯域に余裕があり過ぎだが、２^{（ｐ−１）}ＱＡＭでは、要求される周波数帯域に入らない場合に、それらの中間の変調方式を提供する事ができる。その結果、周波数の有効利用が図れると共に２^ｐＱＡＭに比べて少ない所用の信号対雑音比で２^{（ｐ−１）}ＱＡＭが実現できる為に、電力の有効利用にもなる。
【図面の簡単な説明】
【図１】本発明の第１の実施例を説明するための図である。
【図２】本発明の第２の実施例を説明するための図である。
【図３】本発明の第３の実施例を説明するための図である。
【図４】本発明の第４の実施例を説明するための図である。
【図５】本発明の第５の実施例を説明するための図である。
【図６】本発明の第６の実施例を説明するための図である。
【図７】本発明と従来技術における伝送ビット数を比較して説明するための図である。
【図８】本発明と従来技術における伝送効率を比較して説明するための図である。
【図９】本発明の多値変調回路の構成を示す図である。
【図１０】本発明の多値復調回路の構成を示す図である。
【図１１】本発明の変調方法の手順を示す流れ図である。
【図１２】本発明の復調方法の手順の一例を示す流れ図である。
【符号の説明】
１入力端子
２データ列数変換回路
３第１のデータ変換回路
４第２のデータ変換回路
５並列直列変換回路
６多値変調器
７出力端子
１１入力端子
１２多値復調器
１３直列並列変換回路
１４データ逆変換回路
１５出力端子
１００多値変調装置
２００多値復調装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilevel modulation method and a multilevel demodulation method and apparatus.
[0002]
[Prior art]
Multi-level modulation is particularly used in digital microwave communication and the like, and in the conventional multi-level modulation technology, 2 such as 4QAM, 16QAM, 32QAM, 64QAM, 128QAM, 256QAM,.ⁿQAM has been used.
[0003]
In such digital microwave communication, etc., 4QAM, 16QAM, 32QAM, 64QAM, 128QAM, 256QAM, etc. have been used because of the simplicity of the circuit. The difficulty of implementation due to the complexity of the circuit is being reduced. Furthermore, there is a growing demand for effective use of frequencies and effective use of transmission power.
[0004]
In order to meet this demand, for example, a configuration has been proposed in which an input data string is assigned to two or more general modulation symbols (see, for example, Patent Document 1 below). Japanese Patent Laid-Open No. 04-196945 discloses whether M and N are integers equal to or greater than 2, P is equal to 1 or greater than 1 and less than N, and Q is equal to 1. Or an integer greater than 1, and the input single or plural binary data strings are converted into M × N + P strings, and N values A₁, A₂... A_N2 each^{M +} ^{P / N}Is approximately equal to A₁To A_NProduct up to 2^{M × N + P}, The M × N + P binary data string is represented by the value A₁~ A_NAre converted so as to be expressed by a combination of N sets of binary data strings of M + Q columns corresponding to, and each of these N sets of binary data strings of M + Q columns is converted to a binary data string of one set of M + Q columns. Input a binary data string of one set of M + Q columns, and value A at each time₁~ A_NIs a method of performing multilevel modulation by arranging a number of signal points corresponding to the phase plane (N = 2, M = 4, P = 1, Q = 1, A₁= 24, A₂= 24) is disclosed.
[0005]
The method described in the following Patent Document 1 only shows a general configuration, and does not indicate a specific configuration method when allocating input signal sequences to n phase planes (modulation symbols). Absent.
[0006]
Also known is a method that realizes transmission of p + 1/2 bits per symbol (Symbol) (see Patent Document 2). In other words, 2p + 1 column input data signals are converted into two p + 1 column signals and assigned on the phase plane, the two phase planes are multiplexed as a set, multi-value modulated and transmitted, and one set is formed at this time. By giving a predetermined relationship to the allocation of coordinates on the two phase planes, a configuration in which p + 0.5 bits are allocated to one symbol is realized.
[0007]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 04-196945 (2nd page, FIG. 1)
[Patent Document 2]
JP 2003-60724 A (page 3-4, FIG. 1-5)
[0008]
[Problems to be solved by the invention]
The object of the present invention is to set the multi-value number to 2^{(P + q / n)}It is an object of the present invention to provide a modulation method and a demodulation method and apparatus for obtaining values.
[0009]
Another object of the present invention is to provide a modulation method and a demodulation method that improve a symbol error rate (SER).
[0010]
[Means for Solving the Problems]
The present invention for achieving the above object
The number n of phase planes used is an integer greater than or equal to 2,
p is a predetermined natural number determined in advance,
P is 2^pIs a natural number,
q is a predetermined natural number that is 0 <q <n,
Q is 2^q ^/ ⁿAs a number that is approximately equal to PxQ and is a natural number, one phase plane has at most a natural number of signal points equal to PxQ,
2 over the entire n phase planes^{(Nxp + q)}A modulation method for transmitting individual signals,
On each phase plane, PxQ signal points are converted to P 2^pSignal points (referred to as “internal signal points”) and (PxQ−P) 2^p ⁺ ^q ^/ ⁿ-2^pDividing into signal points approximately equal to ("external signal points");
Using only the internal signal points on all n phase planes;
Of the n phase planes, the external signal points are used on i (where 1 = <i <n) phase planes, and the internal signal points are used on the remaining (ni) phase planes. , And the total of n phase planes is 2^{(Nxp + q)}Transmitting different types of signal points;
including.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described. In the present invention, n is an integer of 2 or more (the number of phase planes to be used), p is a predetermined natural number, and P is 2^pIs a natural number, q is a predetermined natural number that is 0 <q <n, and Q is 2^q ^/ ⁿAs a number that is approximately equal to PxQ and is a natural number, one phase plane has at most a number of signal points equal to PxQ, and the total number of n phase planes is 2^{(Nxp + q)}In a modulation method for transmitting a number of signals, P × Q signal points are represented by P number 2 on each phase plane.^pAnd (PxQ-P) 2^p ⁺ ^q ^/ ⁿ-2^p(The former is referred to as “internal signal point” and the latter is referred to as “external signal point”), and only one internal signal point is used in all n phase planes and one or more n signal points. In the case of using the external signal points only in the following phase planes and using the internal signal points in the remaining phase planes, the total of n phase planes is 2^{(Nxp + q)}Transmits various types of signal points. Multivalued number is 2^{(P + q / n)}It becomes.
[0012]
According to an embodiment of the present invention, n = 4, p ≧ 2, q = 1, and Q is 2¹ ^/ ⁴PxQ = 5 × 2⁽ ^p ^-2)As a natural number, PxQ = 5 × 2 on four (n = 4) phase planes⁽ ^p ^-2)2 signal points on all 4 phase planes^pIn the first case using one internal signal point, one of the four phase planes is selected sequentially, and only 2 on that phase plane.⁽ ^p ^-2)The second case of using the external signal points and using the internal signal points in the remaining three phase planes is divided into 2 as a whole.^{(4xp + 1)}Transmit the signal points.
[0013]
In the case of all internal signal points, (2^p)ⁿ= 2^4pNumber of signal points can be transmitted. There are four types of selection of one phase plane, and the number of external signal points is 2.⁽ ^p ^-2)Therefore, the number of signal points that can be transmitted is 4 × 2⁽ ^p ^-2)x (2^p)^n-1= 2^4pNumber of signal points can be transmitted. Overall, on 4 (n = 4) phase planes, 2^4p ⁺ ¹Transmitting various types of signal points.
[0014]
That means
2^4xp+2^4xp= 2^(4xp ⁺ ¹⁾
It is.
[0015]
According to an embodiment of the present invention, n = 3, p ≧ 3, q = 1, and Q is 2¹ ^/ ³PxQ = 11 × 2 with a number almost equal to⁽ ^p ^- ³ ⁾As a natural number, PxQ = 11 × 2 on three (n = 3) phase planes⁽ ^p ^- ³ ⁾2 signal points on all 3 phase planes^pIn the first case using one internal signal point, one of the three phase planes is selected in sequence, and 2 × 2 only on one phase plane⁽ ^p ^- ³ ⁾Using 6 external signal points and 6x2 for the remaining 2 phase planes⁽ ^p ^- ³ ⁾Pieces and 8x2⁽ ^p ^- ³ ⁾In the second case using two internal signal points, two of the three phase planes are sequentially selected, and 3 × 2 only on the two phase planes⁽ ^p ^- ³ ⁾Using 8 external signal points, the remaining one phase plane is 8x2⁽ ^p ^- ³ ⁾In the third case using 3 internal signal points and 2 × 2 in all 3 phase planes⁽ ^p ^- ³ ⁾Dividing the fourth case using the number of external signal points, 2 as a whole^{(3xp + 1)}Transmits various types of signal points.
[0016]
In the first case, in the case of all internal signal points,
(2^p)ⁿ= 2^3pNumber of signal points can be transmitted.
[0017]
In the second case, there are three types of selection of one phase plane (₃C₁= 3) Yes, 3x2⁽ ^p ^- ³ ⁾2x2 of the external signal points⁽ ^p ^- ³ ⁾Are used as external signal points, and the internal signal points in the two phase planes are 6 × 2⁽ ^p ^- ³ ⁾And 8x2⁽ ^p ^- ³ ⁾By using a number of internal signal points,
3x (2x2⁽ ^p ^- ³ ⁾) X (6x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾)
= 9x2^(3xp-4)
Number of signal points can be transmitted.
[0018]
In the third case, there are three types of selection of two phase planes (₃C₂= 3) Yes, 3x2⁽ ^p ^- ³ ⁾3x2 of the external signal points⁽ ^p ^- ³ ⁾As an internal signal point on one phase plane using 8 × 2 as external signal points,⁽ ^p ^- ³ ⁾By using signal points
3x (3x2⁽ ^p ^- ³ ⁾) X (3x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾)
= 27x2^(3xp-6)
Number of signal points can be transmitted.
[0019]
In the fourth case, the selection of the three phase planes is one type (₃C₃= 1) Yes, 3x2⁽ ^p ^- ³ ⁾2x2 of the external signal points⁽ ^p ^- ³ ⁾By using them on all phase planes as external signal points,
1x (2x2⁽ ^p ^- ³ ⁾) X (2x2⁽ ^p ^- ³ ⁾) X (2x2⁽ ^p ^- ³ ⁾)
= 2^(3xp-6)
Number of signal points can be transmitted.
[0020]
Overall, on 3 (n = 3) phase planes, 2^3xp ⁺ ¹Signal points are transmitted.
[0021]
That means
2^3xp+ 9x2^(3xp-4)+ 27x2^(3xp-6)+2^(3xp-6)
= 2^3xp ⁺ ¹
It is.
[0022]
According to the embodiment of the present invention, n = 2, p ≧ 1, q = 1, and Q is 2¹ ^/ ²PxQ = 3x2 with a number approximately equal to^(P-1)As a natural number, PxQ = 3 × 2 on two (n = 2) phase planes^(P-1)2 signal points in all 2 phase planes^pIn the first case using one internal signal point, one of two phase planes is selected in sequence, and 1 × 2 only on one phase plane^(P-1)Use 2 external signal points and 2x2 for the remaining 1 phase plane^(P-1)Separately from the second case using two internal signal points, 2 as a whole^{(2xp + 1)}Transmits various types of signal points.
[0023]
In the first case, in the case of all internal signal points, (2^p)ⁿ= 2^2pNumber of signal points can be transmitted.
[0024]
In the second case, there are two types of selection of one phase plane (₂C₁= 2) Yes, 1x2^(P-1)1x2 of the external signal points^(P-1)Are used as external signal points, and the internal signal points are 2x2^(P-1)By using a number of internal signal points,
2x (1x2^(P-1)) X (2x2^(P-1)) = 2^(2xp)
Number of signal points can be transmitted.
[0025]
Overall, on 2 (n = 2) phase planes, 2^(2xp ⁺ ¹⁾Signal points are transmitted.
[0026]
That means
2^2p+2^2p= 2^2p ⁺ ¹
It is.
[0027]
According to an embodiment of the present invention, n = 3, p ≧ 2, q = 2, and Q is 2² ^/ ³PxQ = 7x2⁽ ^p ^-2)As a natural number, PxQ = 7 × 2 on three (n = 3) phase planes⁽ ^p ^-2)2 signal points on all 3 phase planes^pIn the first case using one internal signal point, one of the three phase planes is selected sequentially, and 3 × 2 only on one phase plane⁽ ^p ^-2)Using 4 external signal points, the remaining 2 phase planes are 4x2⁽ ^p ^-2)In the second case using two internal signal points, two of the three phase planes are sequentially selected, and 3 × 2 only on the two phase planes⁽ ^p ^-2)2x2 out of external signal points⁽ ^p ^-2)4x2 for the remaining one phase plane⁽ ^p ^-2)Separately from the third case of using internal signal points, 2^{(3xp + 2)}Transmits various types of signal points.
[0028]
In the first case, in the case of all internal signal points, (2^p)ⁿ= 2^3pNumber of signal points can be transmitted.
[0029]
In the second case, there are three types of selection of one phase plane (₃C₁= 3) Yes, 3x2⁽ ^p ^-2)3x2 of the external signal points⁽ ^p ^-2)Are used as external signal points, and the internal signal points in the two phase planes are 4 × 2⁽ ^p ^-2)By using a number of internal signal points,
3x (3x2⁽ ^p ^-2)) X (4x2⁽ ^p ^-2)) X (4x2⁽ ^p ^-2))
= 9x2^(3xp-2)
Number of signal points can be transmitted.
[0030]
In the third case, there are three types of selection of two phase planes (₃C₂= 3) Yes, 3x2⁽ ^p ^- ³ ⁾2x2 of the external signal points⁽ ^p ^-2)Are used as external signal points, and the internal signal points in one phase plane are 4 × 2⁽ ^p ^-2)By using signal points
3x (2x2⁽ ^p ^-2)) X (2x2⁽ ^p ^-2)) X (4x2⁽ ^p ^-2))
= 3x2^(3xp-2)
Number of signal points can be transmitted.
[0031]
Overall, on 3 (n = 3) phase planes, 2^(3xp-2)Signal points are transmitted.
[0032]
That means
2^3p+ 9x2^(3xp-2)+ 3x2^(3xp-2)
= 2^3xp ⁺ ²
It is.
[0033]
According to an embodiment of the present invention, n = 4, p ≧ 3, q = 3, and Q is 2³ ^/ ⁴PxQ = 14x2 with a number approximately equal to⁽ ^p ^- ³ ⁾As a natural number, PxQ = 14 × 2 on four (n = 4) phase planes⁽ ^p ^- ³ ⁾2 signal points on all 4 phase planes^pThe first case using one internal signal point and one of the four phase planes are sequentially selected, and 6 × 2 only on one phase plane⁽ ^p ^- ³ ⁾Using 8 external signal points, the remaining 3 phase planes are 8x2⁽ ^p ^- ³ ⁾The second case using two internal signal points and two of the four phase planes are sequentially selected, and 6 × 2 only on the two phase planes.⁽ ^p ^- ³ ⁾Using 8 external signal points and 8x2 for the remaining 2 phase planes⁽ ^p ^- ³ ⁾In the third case using three internal signal points, three of the four phase planes are selected in sequence, and 4 × 2 only on the three phase planes.⁽ ^p ^- ³ ⁾Pieces and 4x2⁽ ^p ^- ³ ⁾Pieces and 5x2⁽ ^p ^- ³ ⁾Using 8 external signal points and 8x2 for the remaining 1 phase plane⁽ ^p ^- ³ ⁾Dividing the fourth case using the internal signal points, 2 as a whole^{(4xp + 3)}Transmits various types of signal points.
[0034]
In the case of all internal signal points, (2^p)ⁿ= 2^4pNumber of signal points can be transmitted.
[0035]
In the second case, there are four types of selection of one phase plane (₄C₁= 4) Yes, 6x2⁽ ^p ^- ³ ⁾6x2 of the external signal points⁽ ^p ^- ³ ⁾The internal signal points on the three phase planes are 8 × 2⁽ ^p ^- ³ ⁾By using a number of internal signal points,
4x (6x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾)
= 3x2^4xp
Number of signal points can be transmitted.
[0036]
In the third case, there are six types of selection of two phase planes (₄C₂= 6) Yes, 6x2⁽ ^p ^- ³ ⁾6x2 of the external signal points⁽ ^p ^- ³ ⁾Are used as external signal points, and the internal signal points in the two phase planes are 8 × 2⁽ ^p ^- ³ ⁾By using signal points
6x (6x2⁽ ^p ^- ³ ⁾) X (6x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾)
= 27x2^(4xp- ^Three ⁾
Number of signal points can be transmitted.
[0037]
In the fourth case, the selection of the three phase planes is one type (₄C₃= 4) Yes, 6x2⁽ ^p ^- ³ ⁾4x2 of the external signal points⁽ ^p ^- ³ ⁾4x2⁽ ^p ^- ³ ⁾Pieces and 5x2⁽ ^p ^- ³ ⁾Are used as external signal points and the remaining phase plane is 8x2⁽ ^p ^- ³ ⁾By using a number of internal signal points,
4x (4x2⁽ ^p ^- ³ ⁾) X (4x2⁽ ^p ^- ³ ⁾) X (5x2⁽ ^p ^- ³ ⁾) X (8x2⁽ ^p ^- ³ ⁾)
= 5x2^(4xp- ^Three ⁾Number of signal points can be transmitted.
[0038]
Overall, on 4 (n = 4) phase planes, 2^4p ⁺ ³Signal points are transmitted.
[0039]
That means
2^4xp+ 3x2^4xp+ 27x2^(4xp- ^Three ⁾+ 5x2^(4xp-3)
= 2^(4xp ⁺ ³⁾
It is.
[0040]
In any of the above embodiments, the total number of phase planes is n.^{(Np + q)}Value signal, and on average one phase plane is 2^{(P + q / n)}A value signal is transmitted.
[0041]
Therefore, conventionally, in multilevel modulation, n such as 4QAM, 16QAM, 32QAM, 64QAM, 128QAM, 256QAM,.ⁿAlthough QAM has been used, the present invention reduces the multi-value number to 2^{(P + q / n)}It is possible to make it a value.
[0042]
The effect is 2^pQAM has too much frequency bandwidth, but 2^(P-1)QAM can provide an intermediate modulation scheme when it does not fall within the required frequency band. As a result, the frequency can be effectively used and 2^pCompared to QAM, it has a small signal-to-noise ratio and 2^(P-1)Since QAM can be realized, power can be effectively used.
[0043]
According to the present invention, when p + 1/2 bit transmission is realized per phase plane (Symbol), the symbol error rate SER (Symbol Error Rate) is about 0. 14 dB excellent.
[0044]
【Example】
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining signal point transmission when the number of phase planes is n = 4, p = 4, q = 1, and PxQ = 20 as the first embodiment of the present invention. p = 4 for p ≧ 2, p = 1 for 0 <q <4, P = 2⁴= 16, Q is 5/4, PxQ = 5x2⁽ ^p ^-2)= 20. FIG. 1 is a diagram showing modulation symbol mapping, in which the first to fourth modulation symbols output from the multilevel modulator are expressed as so-called constellations (modulation wave signal arrangement points) on the phase plane. It is a signal diagram. In FIG. 1, the coordinate points that the first to fourth symbols can take are indicated by black dots.
[0045]
On 4 (n = 4) phase planes, PxQ = 20 signal points
(A) 16 = 2 for all four phase planes⁴The first case using two internal signal points (2⁴x2⁴x2⁴x2⁴)When,
(B) Select one of the four phase planes in sequence and select 2 on the phase plane only.⁽ ^p ^-2)= 2nd case using 4 external signal points and using internal signal points in the remaining 3 phase planes (4x2⁴x2⁴x2⁴)When,
Separate. In FIG. 1, 16 = 2⁴The internal signal points of the points correspond to signal point arrangement (mapping) of 16QAM (quadrature amplitude modulation) modulated waves. The four external signal points correspond to signal points outside the 16QAM signal point arrangement.
[0046]
In the first case (FIG. 1A),
In the second case (FIG. 1B), how to select the phase plane of the external signal point₄C₁(= 4 ways)
Overall,
2⁴x2⁴x2⁴x2⁴+ 4x4x2⁴x2⁴x2⁴= 2x2⁴x2⁴x2⁴x2⁴= 2x2⁴x2⁴x2⁴x2⁴= 2^{(4x4 + 1)}Transmits various types of signal points.
[0047]
For one phase plane, an average of 2^{(4x4 + 1) / 4}= 2^4.25Signal of value, 2 in total with 4 phase planes¹⁷A value signal can be transmitted.
[0048]
FIG. 2 is a diagram for explaining a case where the number of phase planes is n = 3, p = 4, q = 1, and PxQ = 22 as the second embodiment of the present invention.
[0049]
p = 4, p = 4, 0 <q <3, q = 1, P = 2⁴= 16, Q is 11/8, PxQ = 11x2⁽ ^p ^- ³ ⁾= 11 × 2 = 22.
[0050]
On 3 (n = 3) phase planes, PxQ = 22 signal points are
(A) 2 for all three phase planes^p= 2⁴The first case using two internal signal points (2⁴x2⁴x2⁴)When,
(B) Select one of the three phase planes in sequence and 2 × 2 with only one phase plane⁽ ^p ^- ³ ⁾= 2x2 external signal points, 6x2 for the remaining two phase planes⁽ ^p ^- ³ ⁾= 6x2 and 8x2⁽ ^p ^- ³ ⁾= The second case using 8x2 internal signal points;
(C) Two of the three phase planes are selected in sequence, 3 × 2 only with the two phase planes⁽ ^p ^- ³ ⁾= 3x2 = 6 external signal points, 8x2 for the remaining one phase plane⁽ ^p ^- ³ ⁾= The third case using 8x2 internal signal points;
(D) 2 × 2 for all three phase planes⁽ ^p ^- ³ ⁾= 2x2 = 4th case using 4 external signal points;
Separate.
[0051]
In the first case (see FIG. 2A), one way,
In the second case (see FIG. 2B),₃C₁(= 3 ways)
In the third case (see FIG. 2C),₃C₂= 3 ways
In the fourth case (see FIG. 2D),₃C₃= 1 way.
[0052]
Overall,
2⁴x2⁴x2⁴+ 3x4x (6x2) x (8x2) + 3x6x6x (8x2) + 1x4x4x4
= 4096 + 2304 + 1728 + 64 = 8192 = 2^{(3x4 + 1)}Transmits various types of signal points.
[0053]
For one phase plane, an average of 2^{(3x4 + 1) / 3}= 2^4.33Value signal, 2 in total with 3 phase planes¹³A value signal can be transmitted.
[0054]
FIG. 3 is a diagram for explaining a case where the number of phase planes n = 2, p = 4, q = 1, and PxQ = 24 as the third embodiment of the present invention. P = 2⁴, Q is 3/2, PxQ = 3x2^(P-1)= 3x2³= 24.
[0055]
On two (n = 2) phase planes, PxQ = 3x2³Number of signal points
(A) 2 for all two phase planes⁴A first case using two internal signal points;
(B) Select one of the two phase planes in sequence and 1 × 2 with only one phase plane³Using 2 external signal points and 2x2 for the remaining phase plane³The second case using the internal signal points is separated.
[0056]
In the first case (see FIG. 3A), there is one way, and the number of signal points is 16 × 16 = 256,
In the second case (see FIG. 3B), there are two ways (₂C₁), The number of signal points is 2 × 8 × 16 = 256, and the total number of signal points is
256 + 256 = 512 = 2⁹Types of signal points are transmitted.
[0057]
An average of 2 for one phase plane^9/2= 2^4.5Signal of value and 2 phase planes as a whole⁹A value signal can be transmitted.
[0058]
FIG. 4 is a diagram for explaining the case of n = 3, p = 4, q = 2, and PxQ = 28 as the fourth embodiment of the present invention. P = 2⁴, Q is 7/4, PxQ = 7x2⁽ ^p ^-2)(= 28).
[0059]
On 3 (n = 3) phase planes, PxQ = 28 signal points
(A) 2 for all three phase planes⁴A first case using two internal signal points;
(B) Select one of the three phase planes in sequence, and 3 × 2 with only one phase plane²4x2 for the remaining two phase planes using 1 external signal point²A second case using two internal signal points;
(C) Two of the three phase planes are selected in sequence, and 3 × 2 with only two phase planes⁴2x2 out of external signal points²4x2 for the remaining one phase plane²A third case using one internal signal point;
Separate.
[0060]
In the first case (see FIG. 4A), there is one (2⁴x2⁴x2⁴= 4096),
In the second case (see FIG. 4B), there are three ways (₃C₁Yes (3x3x2)²x4x2²x4x2²= 9216),
In the third case (see FIG. 4C), there are three ways (₃C₂Yes (3x2x2²x2x2²x4x2²= 3072),
Overall,
4096 + 9216 + 3072 = 16384 = 2^{(3x4 + 2)}Transmits various types of signal points.
[0061]
For a single phase plane, on average, 2^{(3x4 + 2) / 3}= 2^4). ⁶⁷Value signal, 2 in total with 3 phase planes¹⁴A value signal can be transmitted.
[0062]
FIG. 5 is a diagram for explaining the case of n = 4, p = 4, q = 3, and PxQ = 28 as the fifth embodiment of the present invention. P = 2⁴, Q is 7/4, PxQ = 14x2⁽ ^p ^- ³ ⁾= 28.
[0063]
On four (n = 4) phase planes, PxQ = 14x2¹= 28 signal points,
(A) 2 for all four phase planes⁴A first case using two internal signal points;
(B) Select one of the four phase planes sequentially, and 6 × 2 with only one phase plane¹Using 8 external signal points and 8x2 for the remaining 3 phase planes¹A second case using two internal signal points;
(C) Select two of the four phase planes sequentially, and 6 × 2 only on the two phase planes¹8x2 for the remaining two phase planes, using 1 external signal point¹A third case using one internal signal point;
(D) Three of the four phase planes are selected in sequence and 4 × 2 only on the three phase planes¹Pieces and 4x2¹And 5x2¹Using 8 external signal points and 8x2 for the remaining phase plane¹A fourth case using two internal signal points;
Separate.
[0064]
In the first case (see FIG. 5A), 2⁴x2⁴x2⁴x2⁴= 65536,
In the second case (see FIG. 5B),₄C₁= 4 types, 4x (6x2¹) X (8x2¹) X (8x2¹) X (8x2¹) = 196608,
In the third case (see FIG. 5C),₄C₂= 6 ways, 6x (6x2¹) X (6x2¹) X (8x2¹) X (8x2¹) = 221184,
In the fourth case (see FIG. 5D),₄C_Three= 4 types, 4x (4x2¹) X (4x2¹) X (5x2¹) X (8x2¹) = 40960,
Overall,
65536 + 196608 + 221184 + 40960 = 524288 = 2¹⁹= 2^{(4x4 + 3)}Transmits various types of signal points.
[0065]
For a single phase plane, on average, 2^{(4x4 + 3) / 4}= 2^4.75Signal of value, 2 in total with 4 phase planes¹⁹A value signal can be transmitted.
[0066]
In the transmission of p + 1/2 bit per symbol in the above-mentioned Patent Document 2, a multi-level modulation is provided in which one phase plane is not necessarily a natural power of 2 using a plurality of phase planes. The phase plane is divided into cases, and the maximum number of signal points is arranged on the other phase planes.
[0067]
In the present invention, the internal signal point and the external signal point are divided on each phase plane, and a part of information is put on the combination of phase planes using the external signal point.
[0068]
According to the present invention, the signal multi-value number is not made a power of 2 to a natural number, for example, 16 (= 2⁴) And 32 (= 2⁵) Is a multilevel modulation method in which 24 is a multilevel number.
[0069]
According to the present invention, in the case of this 24-value modulation, 16 signal points that are the powers of 2 that are the largest natural numbers smaller than 24 are used as internal signal points, and the other 8 (= 24-16) signal points are used as external signal points. As a point, information is also added to the number and position of external signal points to achieve efficient transmission.
[0070]
As a result, in the n phase planes, a total of 2^{(Nxp + q)}Value signal, 2 on average on one phase plane^{(P + q / n)}A value signal is transmitted.
[0071]
As the effect, as shown in FIG.ⁿCompared to the value QAM, intermediate multilevel transmission can be realized.
[0072]
As shown in FIG. 6, BPSK transmits 1-bit information per symbol, QPSK transmits 2-bit information per symbol, and 8PSK transmits 3-bit information per symbol. 2ⁿThe transmission efficiency of the value QAM is 4 bits / symbol for 16QAM, 5 bits / symbol for 32QAM, and 6 bits / symbol for 64QAM. Thus, in the multi-value transmission method, the amount of information that can be transmitted on one phase plane is 2 in the prior art.ⁿThe value QAM was a discrete value of n bits / symbol. In the modulation realized by the present invention, the transmission efficiency (the number of bits of information transmitted per symbol) realizes an intermediate value of discrete values.
[0073]
The invention described in Patent Document 2 also realizes transmission of p + 1/2 bits per one phase plane (Symbol). However, the present invention has a symbol error rate SER (Symbol Error Rate). In point, it is excellent by about 0.14 dB. The total power of 24QAM according to the present invention is 11.46 dB (= 10 log14), whereas in the case of Patent Document 2, it is 11.60 dB.
[0074]
This is because, in the present invention, the signal point on the phase plane is divided into internal signal points and external signal points, and information is added to the number and position of the external signal points, thereby reducing the transmission power. This is because.
[0075]
Moreover, the concrete parameter of this invention in p = 1-6 is shown in FIG. 7, FIG.
[0076]
For example, in FIG. 7, when p = 4, n = 2, and q = 1, 24QAM is realized. When the number of external signal points is 0, 16 phase points are selected as the internal signal points in the two phase planes. When the number of external signal points is 1, the phase plane using the external signal points is sequentially selected. At the same time as using 8 points as external signal points, 16 points are used as internal signal points on the other phase plane.
[0077]
In total, (16 × 16) + 2 × (8 × 16) = 512 types of binary signals can be transmitted on the two phase planes. 512 = 2⁹2 for two phase planes⁹Since the value is transmitted, it is 2 on average on one phase plane.^4.5Value transmission.
[0078]
FIG. 9 is a block diagram showing the configuration of the multilevel modulation device (100) of the first embodiment of the present invention. n phase planes, total 2^{(Nxp + q)}Value signal, and on average one phase plane is 2^{(P + q / n)}A value signal is transmitted.
[0079]
Number of phase planes n = 4, p ≧ 2, q = 1, Q is 2¹ ^/ ⁴PxQ = 5 × 2⁽ ^p ^-2)As a natural number, PxQ = 5 × 2 on four (n = 4) phase planes⁽ ^p ^-2)2 signal points on all 4 phase planes^pIn the first case using one internal signal point (see FIG. 1A), one of the four phase planes is selected in sequence, and only 2 on one phase plane.⁽ ^p ^-2)The second case (see FIG. 1B) in which the external signal points are used and the internal signal points are used on the other three phase planes is divided into 2 as a whole.^{(4xp + 1)}Transmit the signal points. For all internal signal points, (2^p)⁴= 2^4pNumber of signal points can be transmitted. There are four types of selection of one phase plane, and the number of external signal points is 2.⁽ ^p ^-2)Therefore, the number of signal points that can be transmitted is 4 × 2⁽ ^p ^-2)x (2^p)^n-1= 2^4pNumber of signal points can be transmitted. Overall, on 4 (n = 4) phase planes, 2^4p+2^4p= 2^4xp ⁺ ¹Transmitting various types of signal points. Referring to FIG. 9, the multilevel modulation device 100 of this embodiment includes an input terminal 1, a data string number conversion circuit 2, a first data conversion circuit 3, a second data conversion circuit 4, and a parallel series. A conversion circuit 5, a multilevel modulator 6, and an output terminal 7 are provided. In the following, the configuration for performing multilevel modulation shown in FIG. 1 will be described as an example. For details of the multi-level modulation device 100, for example, the description in the above-mentioned Patent Document 2 is referred to.
[0080]
The first data conversion circuit 3 and the second data conversion circuit 4 convert the input data signal 21 of, for example, 4p + 1 columns (bit width) output from the data column number conversion circuit 2. The first data conversion circuit 3 outputs a p + 1 column signal in accordance with the value of the input data signal 21. The second data conversion circuit 4 receives the output signal of the first data conversion circuit 3, refers to the value of the input data signal 21, determines the presence or absence of a phase plane using the external signal point, and sets the external signal point. When the number of phase planes used is 0, four converted data signals (first to fourth modulation symbols) 41 according to the mapping shown in FIG.₁~ 41_n(N = 4) is output. The second data conversion circuit 4 receives the output signal of the first data conversion circuit 3 and refers to the value of the input data signal 21. When the number of phase planes using external signal points is 1, Four converted data signals (first to fourth modulation symbols) 41 according to the mapping shown in 1 (B)₁~ 41_n(N = 4) is output. The conversion in the first and second data conversion circuits 3 and 4 is performed by a table look-up method that performs conversion by referring to a memory such as a ROM (read only memory). The parallel-serial conversion circuit 5 receives the output signal of the second data conversion circuit 4 and time-division multiplexes, and outputs a p + 1 column multiplexed signal 51. The multi-level modulator 6 multi-level modulates the carrier wave based on the modulation symbol transmitted as the multiplexed signal 51 and outputs it to the output terminal 7. Of course, the first and second data conversion circuits 3 and 4 may be configured as one conversion circuit.
[0081]
FIG. 10 is a block diagram showing the configuration of the multilevel demodulator (200) according to the first embodiment of the present invention. Referring to FIG. 10, the multilevel demodulator 200 according to the present embodiment includes an input terminal 11, a multilevel demodulator 12, a serial / parallel converter circuit 13, a data inverse converter circuit 14, and an output terminal 15. ing. The multilevel demodulator (200) in FIG. 10 receives and demodulates the signal transmitted from the multilevel modulator (100) in FIG.
[0082]
The multilevel demodulator 12 demodulates the communication signal input to the input terminal 11 and outputs, for example, a received demodulated data sequence signal 121 of p + 1 sequence. The serial-to-parallel conversion circuit 13 time-division demultiplexes the received demodulated data string signal 121 to n (n = 4) demodulated data string signals 131 each having p + 1 columns.₁~ 131_nIs output. The data inverse conversion circuit 14 includes first to n-th demodulated data string signals 131.₁~ 131_nAnd the demodulated data string signal 141 is output. Here, the data inverse conversion circuit 14 is based on, for example, the value of the first demodulated data string signal. For example, when the external signal point is not used according to the symbol mapping shown in FIG. 2 which are respectively predetermined as demodulated data string signals of^4pUpon receiving the signal indicating the seed value, a predetermined demodulated data value is generated based on the values indicated by the first, second, third, and fourth demodulated data sequence signals, and the demodulated data value is demodulated in 4p + 1 sequence. Output as a data signal. On the other hand, when the external signal point is used, each of the first to fourth demodulated data string signals is predetermined 2^4pUpon receiving the signal indicating the seed value, a predetermined demodulated data value is generated based on the values indicated by the first, second, third, and fourth demodulated data sequence signals, and the demodulated data value is demodulated in 4p + 1 sequence. Output as a data signal. Inverse transformation in the data inverse transformation circuit 14 is realized by, for example, a table lookup method using a ROM or the like.
[0083]
FIG. 11 is a flowchart for explaining a modulation process according to an embodiment of the present invention. In step S1, an input data signal is input. In step S2, it is determined whether or not an external signal point is used as the signal point arrangement of the modulation symbol based on the input data signal. If no external signal point is used, first to n-th converted data (modulation symbols) are generated in step S4 when internal signal points are used on n phase planes. On the other hand, when the external signal point is used, the first to nth cases in the case where the external signal point is used on the predetermined number of phase planes and only the internal signal points are used on the remaining phase planes in step S3. Conversion data (modulation symbol) is generated. In step S5, n pieces of converted data (modulation symbols) are output to the modulator.
[0084]
In an apparatus for receiving and demodulating a signal modulated by the modulation method of the present invention, the reverse process of the modulation method described above is performed.
[0085]
FIG. 12 is a flowchart for explaining demodulation processing according to an embodiment of the present invention. In step S11, n demodulated data sequence signals are input, and in step S12, based on the first to n-th demodulated data sequence signals, when no external signal points are used as signal point arrangement of modulation symbols, 2 which are predetermined as the first to fourth demodulated data string signals, respectively.^4pReceiving the signal indicating the seed value, the first to fourth demodulated data values are generated based on the values indicated by the first to fourth demodulated data sequence signals, and the demodulated data values are demodulated in 4p + 1 sequence. Output as a data signal. When external signal points are used as the signal point arrangement of modulation symbols, there are four types of selection of one phase plane, and the number of external signal points is 2.⁽ ^p ^-2)4x2 because it is a piece⁽ ^p ^-2)x (2^p)^n-1= 2^4pThe seed value is received as the first to fourth demodulated data string signals, and a predetermined demodulated data value is generated based on the values indicated by the first to fourth demodulated data string signals, and this demodulated data value is, for example, 4 × p + 1. Output as the demodulated data signal of the column.
[0086]
Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the configuration of the above embodiment, and can be made by those skilled in the art within the scope of the principle of the present invention. Of course, various modifications and corrections are included.
[0087]
【The invention's effect】
As explained above, according to the present invention, the total number of phase planes in n phase planes is 2^{(Np + q)}Value signal, average 2 on one phase plane^{(P + q / n)}Value signal and multi-value number 2^{(P + q / n)}It is possible to make it a value.
[0088]
According to the invention, 2^pQAM has too much frequency bandwidth, but 2^(P-1)QAM can provide an intermediate modulation scheme when it does not fall within the required frequency band. As a result, the frequency can be effectively used and 2^pLess signal-to-noise ratio than 2 for QAM^(P-1)Since QAM can be realized, the power can be effectively used.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a first embodiment of the present invention.
FIG. 2 is a diagram for explaining a second embodiment of the present invention.
FIG. 3 is a diagram for explaining a third embodiment of the present invention.
FIG. 4 is a diagram for explaining a fourth embodiment of the present invention.
FIG. 5 is a diagram for explaining a fifth embodiment of the present invention.
FIG. 6 is a diagram for explaining a sixth embodiment of the present invention.
FIG. 7 is a diagram for comparing and explaining the number of transmission bits in the present invention and the prior art.
FIG. 8 is a diagram for comparing and explaining the transmission efficiency in the present invention and the prior art.
FIG. 9 is a diagram showing a configuration of a multilevel modulation circuit of the present invention.
FIG. 10 is a diagram showing a configuration of a multilevel demodulation circuit according to the present invention.
FIG. 11 is a flowchart showing the procedure of the modulation method of the present invention.
FIG. 12 is a flowchart showing an example of a procedure of a demodulation method according to the present invention.
[Explanation of symbols]
1 Input terminal
2 Data string number conversion circuit
3 First data conversion circuit
4 Second data conversion circuit
5 Parallel to serial converter
6 Multi-level modulator
7 Output terminal
11 Input terminal
12 Multilevel demodulator
13 Series-parallel converter
14 Data reverse conversion circuit
15 Output terminal
100 Multilevel modulation device
200 Multilevel demodulator

Claims

The number n of phase planes is an integer greater than or equal to 2,
p is a predetermined natural number determined in advance,
P is a natural number of 2 ^p ,
q is a predetermined natural number that is 0 <q <n,
Exceed approximately equal ^{2 q} ^/ ⁿ the Q to ^{2 q} ^/ ^n, as a number of the PxQ a natural number, having a signal point of a maximum number of PxQ in one phase plane,
A modulation method for transmitting 2 ^{(nxp + q)} signals across n phase planes,
On each phase plane, PxQ signal points are converted to P signal points equal to 2 ^p (referred to as “internal signal points”) and (PxQ−P) 2 ^p ⁺ ^q ^/ ⁿ −2 ^p . Divided into approximately equal signal points ("external signal points")
Using only the internal signal points on all n phase planes;
Among the n phase planes, the external signal points are used on i phase planes (where i is a predetermined integer not less than 1 and less than n), and the internal signal points are used on the remaining (n−i) phase planes. A step of transmitting 2 ^{(nxp + q)} kinds of signal points as a whole of n phase planes;
A multi-level modulation method comprising:

The number n of phase planes is 4,
p is an integer greater than or equal to 2,
q is 1,
Q in the number of more than approximately equal ^{2 ^{^1/4}} to ^{2 ^{^1/4,}} as a natural number of PxQ = 5x2 ^{^(p} ^-2),
On a four phase plane, P × Q = 5x2 for ^{^(p} ^-2) pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all four phase plane,
By sequentially selecting one of the four phase planes and using only one phase plane, PxQ−2 ^p = 2 ⁽ ^p ⁻²⁾ external signal points and the remaining three phase planes 2. The multi-level modulation according to claim 1, wherein the multi-level modulation includes the step of transmitting 2 ^{(4 × p + 1)} signal points as a whole, divided into the second case using 2 ^p internal signal points. Method.

The number n of phase planes is 3,
p is an integer greater than or equal to 3,
q is 1,
Q by the number of more than approximately equal ^{2 ^{^1/3}} to ^{2 ^{^1/3,}} PxQ = 11x2 ^{^-} as a natural number of ^{^(p} ^{^3),}
On the phase plane of the three (n = 3), PxQ = 11x2 (p - 3) for pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all three phase plane ,
Select one of the three phase planes in sequence, use 2x2 ⁽ ^p ^- ³ ⁾ external signal points in only one phase plane, and 6x2 ⁽ ^p ^- ³ ^{) in} the remaining two phase planes and ^{^- ⁽³} ^{^p)} number of second using an internal signal point when, and 8x2
Select two of the three phase planes in sequence, use 3x2 ⁽ ^p ^- ³ ⁾ external signal points in the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals in the remaining one phase plane A third case using signal points;
A fourth case using 2 × 2 ⁽ ^p ⁻ ³ ⁾ external signal points in all three phase planes;
2. The multi-level modulation method according to claim 1, further comprising a step of transmitting 2 ^{(3 × p + 1)} types of signal points as a whole.

Let the number n of phase planes be 2,
p is an integer of 1 or more,
q is 1,
Q by the number of more than approximately equal ^{2 ^{^1/2}} to ^{2 ^{^1/2,}} as a natural number of ^{PxQ = 3x2 (p-1)} ,
On two (n = 2) phase planes, for PxQ = 3 × 2 ^(p−1) signal point arrangements,
A first case using 2 ^p internal signal points on all two phase planes;
One of the two phase plane are sequentially selected, only using a 1x2 ^(p-1) pieces of the external signal point in one phase surface, internal 2x2 ^(p-1) pieces of the remaining one phase plane 2. The multi-level modulation method according to claim 1, further comprising a step of transmitting 2 ⁽ 2 ^{× p + 1)} types of signal points as a whole, which is separated from the second case using signal points.

Let the number n of phase planes be 3,
p is an integer greater than or equal to 2,
Let q be 2,
Q in the number of more than approximately equal ^{2 ^{^2/3}} ^{2 ^{^2/3,}} as a natural number of PxQ = 7x2 ^{^(p} ^-2),
On the phase plane of the three (n = 3), PxQ = 7x2 for ^{^(p} ^-2) pieces of signal point arrangement, when the first use of 2 ^p number of internal signal points in all three phase plane and ,
Select one of the three phase planes in sequence and use 3x2 ⁽ ^p ^-2) external signal points on only one phase plane, and 4x2 ⁽ ^p ^-2) internals on the remaining two phase planes A second case using signal points;
Two of the three phase planes are sequentially selected, and only 2 phase planes are used, and 2x2 ⁽ ^p ^{-2) of} 3x2 ⁽ ^p ^-2) external signal points are used, and the remaining 1 One phase plane is divided from the third case using 4 × 2 ⁽ ^p ⁻²⁾ internal signal points, and includes a step of transmitting 2 ⁽ 3 × ^p ^{+ 2)} types of signal points as a whole. The multi-level modulation method according to claim 1.

Let the number n of phase planes be 4,
Let p be an integer greater than or equal to 3,
q is 3,
Q by the number of more than approximately equal ^{2 ^{^3/4}} to ^{2 ^{^3/4,}} P × Q = 14x2 ^{^-} as a natural number of ^{^(p} ^{^3),}
On the phase plane of the four (n = 4), PxQ = 14x2 - for ^{^(p} ^³⁾ pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all four phase plane,
Select one of the four phase planes sequentially, use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only one phase plane, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining three phase planes A second case using signal points;
Select two of the four phase planes in sequence and use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining two phase planes A third case using signal points;
Four sequentially selects three phase plane, only 4x2 three phase plane ^{^(p} ^{^- ³⁾} number and 4x2 ^{^(p} ^{^- ³⁾} number and 5x2 ^{^(p} ^{^- ³⁾} with a number of external signal points, remaining in one phase faces 8x2 ^{^(p ^-} ^³⁾ number of divided as in the fourth with internal signal points, as a whole, comprises transmitting ² (4xp ^{+ 3)} types of signal points, that characterized The multi-level modulation method according to claim 1.

When P = 2 ^p (where p is a predetermined positive integer) and a predetermined positive integer A between P and 2 × P is expressed as PxQ (where Q is A / P),
Constellation about the modulation symbol, the multi-level number ^{2 p,} PSK corresponding to (phase shift keying), QPSK (quadrature phase shift keying), ^{2 p} number of signal points arranged at either QAM (quadrature amplitude modulation) an internal signal points are signal points, the multi-level number ^{2 p,} PSK (phase shift keying), QPSK (quadrature phase shift keying), ^{2 p} number of signal points arranged at either QAM (quadrature amplitude modulation) And external signal points that are maximum PxQ-2 ^p signal points,
a case where n phase plane signal points consist only of 2 ^p internal signal points;
Of the n phase planes, each of the predetermined number of phase planes includes a predetermined number of the external signal points as signal points, and each of the remaining phase planes as signal points, Cases consisting of only a predetermined number of the internal signal points are divided into cases,
Providing information on a combination of the number of external signal points and a phase plane using the external signal points, generating n modulation symbols, and multi-level modulating a carrier wave with n sets of modulation symbols,
A multi-level modulation method characterized by transmitting 2 ^{(pxn + q)} types of signal points ^{(where q} is an integer satisfying 2 ^{(q / n)} = Q with 0 <q <p).

The number n of phase planes is an integer greater than or equal to 2,
p is a predetermined natural number,
P is a natural number of 2 ^p ,
q is a predetermined natural number that is 0 <q <n,
Exceed approximately equal ^{2 q} ^/ ⁿ the Q to ^{2 q} ^/ ^n, as a number of the PxQ a natural number, having a signal point of a maximum number of PxQ in one phase plane,
A modulation device that transmits 2 ^{(nxp + q)} signals across n phase planes,
On each phase plane, PxQ signal points are converted to P signal points equal to 2 ^p (referred to as “internal signal points”) and (PxQ−P) 2 ^p ⁺ ^q ^/ ⁿ −2 ^p . Divided into approximately equal signal points ("external signal points")
Using only the internal signal points on all n phase planes;
Among the n phase planes, the external signal points are used on i phase planes (where i is a predetermined integer not less than 1 and less than n), and the internal signal points are used on the remaining (n−i) phase planes. And a means for transmitting 2 ^{(nxp + q)} types of signal points as a whole of the n phase planes.

The number n of phase planes is 4,
p is an integer greater than or equal to 2,
q is 1,
Q in the number of more than approximately equal ^{2 ^{^1/4}} to ^{2 ^{^1/4,}} as a natural number of PxQ = 5x2 ^{^(p} ^-2),
On a four phase plane, P × Q = 5x2 for ^{^(p} ^-2) pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all four phase plane,
By sequentially selecting one of the four phase planes and using only one phase plane, PxQ−2 ^p = 2 ⁽ ^p ⁻²⁾ external signal points and the remaining three phase planes ^9. The multi-level modulation according to claim 8, wherein the multi-level modulation includes the step of transmitting 2 ^{(4 × p + 1)} signal points as a whole, divided into the second case using 2 ^p internal signal points. apparatus.

The number n of phase planes is 3,
p is an integer greater than or equal to 3,
q is 1,
Q by the number of more than approximately equal ^{2 ^{^1/3}} to ^{2 ^{^1/3,}} PxQ = 11x2 ^{^-} as a natural number of ^{^(p} ^{^3),}
On the phase plane of the three (n = 3), PxQ = 11x2 (p - 3) for pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all three phase plane ,
Select one of the three phase planes in sequence, use 2x2 ⁽ ^p ^- ³ ⁾ external signal points in only one phase plane, and 6x2 ⁽ ^p ^- ³ ^{) in} the remaining two phase planes and ^{^- ⁽³} ^{^p)} number of second using an internal signal point when, and 8x2
Select two of the three phase planes in sequence, use 3x2 ⁽ ^p ^- ³ ⁾ external signal points in the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals in the remaining one phase plane A third case using signal points;
A fourth case using 2 × 2 ⁽ ^p ⁻ ³ ⁾ external signal points in all three phase planes;
^9. The multilevel modulation device according to claim 8, further comprising means for transmitting 2 ^{(3 × p + 1)} types of signal points as a whole.

Let the number n of phase planes be 2,
p is an integer of 1 or more,
q is 1,
Q by the number of more than approximately equal ^{2 ^{^1/2}} to ^{2 ^{^1/2,}} as a natural number of ^{PxQ = 3x2 (p-1)} ,
On two (n = 2) phase planes, for PxQ = 3 × 2 ^(p−1) signal point arrangements,
A first case using 2 ^p internal signal points on all two phase planes;
One of the two phase plane are sequentially selected, only using a 1x2 ^(p-1) pieces of the external signal point in one phase surface, internal 2x2 ^(p-1) pieces of the remaining one phase plane ^9. The multi-level modulation device according to claim 8, further comprising means for transmitting 2 ⁽ 2 ^{× p + 1)} types of signal points as a whole, which is divided from the second case using signal points.

Let the number n of phase planes be 3,
p is an integer greater than or equal to 2,
Let q be 2,
Q in the number of more than approximately equal ^{2 ^{^2/3}} ^{2 ^{^2/3,}} as a natural number of PxQ = 7x2 ^{^(p} ^-2),
On the phase plane of the three (n = 3), the PxQ = 7x2 ^{^(p} ^-2) pieces of signal points, the first case of using a 2 ^p number of internal signal points in all three phase plane,
Select one of the three phase planes in sequence and use 3x2 ⁽ ^p ^-2) external signal points on only one phase plane, and 4x2 ⁽ ^p ^-2) internals on the remaining two phase planes A second case using signal points;
Two of the three phase planes are sequentially selected, and only 2 phase planes are used, and 2x2 ⁽ ^p ^{-2) of} 3x2 ⁽ ^p ^-2) external signal points are used, and the remaining 1 The two phase planes are separated from the third case using 4 × 2 ⁽ ^p ⁻²⁾ internal signal points, and as a whole, have means for transmitting 2 ⁽ 3 × ^p ^{+ 2)} types of signal points. The multi-level modulation device according to claim 8, wherein:

Let the number n of phase planes be 4,
Let p be an integer greater than or equal to 3,
q is 3,
Q by the number of more than approximately equal ^{2 ^{^3/4}} to ^{2 ^{^3/4,}} P × Q = 14x2 ^{^-} as a natural number of ^{^(p} ^{^3),}
On the phase plane of the four (n = 4), PxQ = 14x2 - a ^{^(p} ^³⁾ pieces of signal points, the first case of using a ^{2 p} number of internal signal points in all four phase plane,
Select one of the four phase planes sequentially, use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only one phase plane, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining three phase planes A second case using signal points;
Select two of the four phase planes in sequence and use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining two phase planes A third case using signal points;
Four sequentially selects three phase plane, only 4x2 three phase plane ^{^(p} ^{^- ³⁾} number and 4x2 ^{^(p} ^{^- ³⁾} number and 5x2 ^{^(p} ^{^- ³⁾} with a number of external signal points, in the remaining one phase faces 8x2 ^{^-} separate the case ^{^(p} ^³⁾ pieces of the fourth using an internal signal points, as a whole, comprises a means for transmitting the ² (4xp ^{+ 3)} types of signal points, that The multi-level modulation device according to claim 8.

When P = 2 ^p (p is a predetermined positive integer) and an integer between P and 2P is expressed as PxQ,
Constellation about the modulation symbol, the multi-level number ^{2 p,} PSK corresponding to (phase shift keying), QPSK (quadrature phase shift keying), ^{2 p} number of signal points arranged at either QAM (quadrature amplitude modulation) an internal signal points are signal points, the multi-level number ^{2 p,} PSK (phase shift keying), QPSK (quadrature phase shift keying), ^{2 p} number of signal points arranged at either QAM (quadrature amplitude modulation) And external signal points that are maximum PxQ-2 ^p signal points,
a case where n phase plane signal points consist only of 2 ^p internal signal points;
Of the n phase planes, each of the predetermined number of phase planes includes a predetermined number of the external signal points as signal points, and each of the remaining phase planes as signal points, According to the case where only a predetermined number of internal signal points are included, the number of external signal points and the phase plane using the external signal points are provided with information, and n modulation symbols are provided. Means for generating;
modulation means for multi-level modulating a carrier wave with n sets of modulation symbols;
A multi-level modulation apparatus characterized by transmitting 2 ^{(pxn + q)} types of signal points as a whole.

A data string conversion circuit for inputting an input data signal and converting it into n data signal strings;
When the first data signal is generated based on the output signal from the data string converter, and the modulation symbol is expressed as a signal point arrangement on the phase plane from the value of the first data signal, the external signal point If the external signal points are not used, the first to nth data signals are output using the internal signal points on the n phase planes, and the external signal points are used. A second data conversion circuit that outputs first to nth data signals using external signal points on a predetermined number of phase planes and internal signal points on the remaining phase planes;
A parallel-serial conversion circuit for parallel-serial conversion of n outputs of the second data conversion circuit;
A modulator that receives the parallel-serial conversion circuit and performs multi-level modulation;
The multi-level modulation apparatus according to claim 8, wherein the multi-level modulation apparatus performs modulation with a multi-level number P × Q.

The number n of phase planes is an integer greater than or equal to 2,
p is a predetermined natural number determined in advance,
P is a natural number of 2 ^p ,
q is a predetermined natural number that is 0 <q <n,
Assuming that PxQ is a natural number with Q almost equal to 2 ^q ^/ ⁿ , one phase plane has at most a natural number of signal points equal to PxQ,
On each phase plane, PxQ signal points are converted to P signal points equal to 2 ^p (referred to as “internal signal points”) and (PxQ−P) 2 ^p ⁺ ^q ^/ ⁿ −2 ^p . Divided into approximately equal signal points ("external signal points")
Using only the internal signal points on all n phase planes;
Among the n phase planes, the external signal points are used on i phase planes (where i is a predetermined integer not less than 1 and less than n), and the internal signal points are used on the remaining (n−i) phase planes. And a multi-level demodulation method for receiving and demodulating a signal from a modulation device that transmits a signal obtained by modulating a carrier wave with n modulation symbols generated separately.
Based on n demodulated data, only the internal signal points are used in all n phase planes, and i out of n phase planes (where i is a predetermined integer greater than or equal to 1 and less than n) Corresponding to the case where the external signal points are used on the phase plane and the internal signal points are used on the remaining (n−i) phase planes, and converted into n conversion data and output. A multi-level demodulation method comprising:

The number n of phase planes is 4,
p is an integer greater than or equal to 2,
q is 1,
Q in the number of more than approximately equal ^{2 ^{^1/4}} to ^{2 ^{^1/4,}} as a natural number of PxQ = 5x2 ^{^(p} ^-2),
On a four phase plane, P × Q = 5x2 for ^{^(p} ^-2) pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all four phase plane,
4 sequentially selects one of the phase plane, the only one phase plane, using a ^{^{^{PxQ-2 p = 2 (p}}} -2) pieces of external signal points, the remaining three phase plane In the second case where 2 ^p internal signal points are used, as a whole, when receiving and demodulating a signal from a modulation device transmitting 2 ^{(4 × p + 1)} signal points,
Based on 4 demodulated data, the first case using 2 ^p internal signal points on all phase planes;
By sequentially selecting one of the four phase planes and using only one phase plane, PxQ−2 ^p = 2 ⁽ ^p ⁻²⁾ external signal points and the remaining three phase planes The multi-level demodulation method according to claim 16, further comprising a step of outputting n pieces of converted data separately from the second case using 2 ^p internal signal points.

The number n of phase planes is 3,
p is an integer greater than or equal to 3,
q is 1,
Q by the number of more than approximately equal ^{2 ^{^1/3}} to ^{2 ^{^1/3,}} PxQ = 11x2 ^{^-} as a natural number of ^{^(p} ^{^3),}
On the phase plane of the three (n = 3), PxQ = 11x2 (p - 3) for pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all three phase plane ,
Select one of the three phase planes in sequence, use 2x2 ⁽ ^p ^- ³ ⁾ external signal points in only one phase plane, and 6x2 ⁽ ^p ^- ³ ^{) in} the remaining two phase planes and ^{^- ⁽³} ^{^p)} number of second using an internal signal point when, and 8x2
Select two of the three phase planes in sequence, use 3x2 ⁽ ^p ^- ³ ⁾ external signal points in the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals in the remaining one phase plane A third case using signal points;
A fourth case using 2 × 2 ⁽ ^p ⁻ ³ ⁾ external signal points in all three phase planes;
As a whole, when receiving and demodulating a signal from a modulation device that transmits 2 ^{(3 × p + 1)} types of signal points,
Based on three demodulated data, the first case using 2 ^p internal signal points in all three phase planes;
Select one of the three phase planes in sequence, use 2x2 ⁽ ^p ^- ³ ⁾ external signal points in only one phase plane, and 6x2 ⁽ ^p ^- ³ ^{) in} the remaining two phase planes and ^{^- ⁽³} ^{^p)} number of second using an internal signal point when, and 8x2
Select two of the three phase planes in sequence, use 3x2 ⁽ ^p ^- ³ ⁾ external signal points in the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals in the remaining one phase plane A third case using signal points;
A fourth case using 2 × 2 ⁽ ^p ⁻ ³ ⁾ external signal points in all three phase planes;
The multi-level demodulation method according to claim 16, further comprising a step of generating three pieces of converted data by dividing

Let n of the phase plane be 2,
p is an integer of 1 or more,
q is 1,
Q by the number of more than approximately equal ^{2 ^{^1/2}} to ^{2 ^{^1/2,}} as a natural number of ^{PxQ = 3x2 (p-1)} ,
On two (n = 2) phase planes, for PxQ = 3 × 2 ^(p−1) signal point arrangements,
A first case using 2 ^p internal signal points on all two phase planes;
One of the two phase plane are sequentially selected, only using a 1x2 ^(p-1) pieces of the external signal point in one phase surface, internal 2x2 ^(p-1) pieces of the remaining one phase plane The second case using signal points is separated from the second case, and as a whole, when receiving and demodulating signals from a modulation device that transmits 2 ⁽ 2 ^{× p + 1)} types of signal points,
Based on two demodulated data, the first case where 2 ^p internal signal points are used in all two phase planes, and one of the two phase planes is selected sequentially, and only on one phase plane. 1x2 ^(p-1) using the number of external signal points, in the remaining one phase plane is divided in the case of the second using 2x2 ^(p-1) pieces of the internal signal points, the two corresponding conversion data The multi-level demodulation method according to claim 16, further comprising: a step of outputting.

Let the number n of phase planes be 3,
p is an integer greater than or equal to 2,
Let q be 2,
Q in the number of more than approximately equal ^{2 ^{^2/3}} ^{2 ^{^2/3,}} as a natural number of PxQ = 7x2 ^{^(p} ^-2),
On the phase plane of the three (n = 3), the PxQ = 7x2 ^{^(p} ^-2) pieces of signal points, the first case of using a 2 ^p number of internal signal points in all three phase plane,
Select one of the three phase planes in sequence and use 3x2 ⁽ ^p ^-2) external signal points on only one phase plane, and 4x2 ⁽ ^p ^-2) internals on the remaining two phase planes A second case using signal points;
Two of the three phase planes are sequentially selected, and only 2 phase planes are used, and 2x2 ⁽ ^p ^{-2) of} 3x2 ⁽ ^p ^-2) external signal points are used, and the remaining 1 The two phase planes are separated from the third case using 4 × 2 ⁽ ^p ⁻²⁾ internal signal points, and as a whole, receive signals from a modulator that transmits 2 ⁽ 3 × ^p ^{+ 2)} types of signal points. When demodulating
Based on three demodulated data, the first case using 2 ^p internal signal points in all three phase planes;
Select one of the three phase planes in sequence and use 3x2 ⁽ ^p ^-2) external signal points on only one phase plane, and 4x2 ⁽ ^p ^-2) internals on the remaining two phase planes A second case using signal points;
Two of the three phase planes are sequentially selected, and only 2 phase planes are used, and 2x2 ⁽ ^p ^{-2) of} 3x2 ⁽ ^p ^-2) external signal points are used, and the remaining 1 17. The method according to claim 16, further comprising a step of generating corresponding conversion data separately from the third case using 4 × 2 ⁽ ^p ⁻²⁾ internal signal points for one phase plane. Value demodulation method.

Let the number n of phase planes be 4,
Let p be an integer greater than or equal to 3,
q is 3,
Q by the number of more than approximately equal ^{2 ^{^3/4}} to ^{2 ^{^3/4,}} P × Q = 14x2 ^{^-} as a natural number of ^{^(p} ^{^3),}
On the phase plane of the four (n = 4), PxQ = 14x2 - for ^{^(p} ^³⁾ pieces of signal point arrangement, as in the first to use a 2 ^p number of internal signal points in all four phase plane,
Select one of the four phase planes sequentially, use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only one phase plane, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining three phase planes A second case using signal points;
Select two of the four phase planes in sequence and use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining two phase planes A third case using signal points;
Four sequentially selects three phase plane, only 4x2 three phase plane ^{^(p} ^{^- ³⁾} number and 4x2 ^{^(p} ^{^- ³⁾} number and 5x2 ^{^(p} ^{^- ³⁾} with a number of external signal points, remaining in one phase faces 8x2 ^{^(p ^-} ^³⁾ number of divided as in the fourth with internal signal points, as a ^whole, 2 (4xp ^{+ 3)} type of the received signals from the modulator for transmitting the signal point And then demodulate
Based on four demodulated data, the first case using 2 ^p internal signal points in all four phase planes;
Select one of the four phase planes sequentially, use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only one phase plane, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining three phase planes A second case using signal points;
Select two of the four phase planes in sequence and use 6x2 ⁽ ^p ^- ³ ⁾ external signal points on only the two phase planes, and 8x2 ⁽ ^p ^- ³ ⁾ internals on the remaining two phase planes A third case using signal points;
Four sequentially selects three phase plane, only 4x2 three phase plane ^{^(p} ^{^- ³⁾} number and 4x2 ^{^(p} ^{^- ³⁾} number and 5x2 ^{^(p} ^{^- ³⁾} with a number of external signal points, in the remaining one phase faces 8x2 ^{^-} separately in the case of ^{^(p} ^³⁾ pieces of the fourth using internal signal point comprises generating the corresponding conversion data, according to claim 16, wherein the Multilevel demodulation method.

When P = 2 ^p (p is a predetermined positive integer) and a predetermined integer between P and 2 × P is expressed as PxQ,
Constellation of one modulation symbol, the multi-level number ^{2 p,} PSK (phase shift keying), QPSK (quadrature phase shift keying), ^{2 p} number of signal points arranged at either QAM (quadrature amplitude modulation) Internal signal points that are signal points corresponding to and / or
A signal point of a predetermined prescribed number of said internal signal point, the multi-level number 2 ^p, PSK (phase shift keying), QPSK (quadrature phase shift keying), either in QAM (quadrature amplitude modulation) A predetermined number of signal points among external signal points that are maximum P × Q−2 ^p signal points arranged outside the 2 ^p signal point arrangements of
Consisting of
Demodulating means for generating n (p + 1) -bit demodulated data signals from a received data signal having a value of 2 ^{(pxn + q)} (2 ^{(q / n)} = Q);
Serial-parallel conversion means for converting n serial outputs of the demodulation means into n parallel outputs;
input n demodulated data signals;
When the signal points of n phase planes consist only of the internal signal points,
Of the n phase planes, each of a predetermined number of phase planes includes a predetermined number of external signal points as signal points, and the remaining phase planes are predetermined as signal points. A predetermined number of the internal signal points only, and
Inverse data conversion means for generating n data corresponding to the combination of
A multi-level modulation device comprising: