JP2005033335A

JP2005033335A - Multiple input multiple output propagation path signal transmitting apparatus and receiving station

Info

Publication number: JP2005033335A
Application number: JP2003193832A
Authority: JP
Inventors: Takeshi Yamada; 武史山田; Shigeru Tomisato; 繁冨里; Hiroto Suda; 博人須田
Original assignee: NTT Docomo Inc
Current assignee: NTT Docomo Inc
Priority date: 2003-07-08
Filing date: 2003-07-08
Publication date: 2005-02-03
Anticipated expiration: 2023-07-08
Also published as: JP4413545B2

Abstract

<P>PROBLEM TO BE SOLVED: To improve the consistency of a transmission/reception weight to reduce the deterioration in transmission characteristics by using a processed transmission weight at the time of generating a reception weight. <P>SOLUTION: In this multiple input multiple output propagation path signal transmitting apparatus, in a receiving station 200, instead of using feedback information not processed at the time of generating the reception weight, processed feedback information which has been processed in a feedback information processor 206 of the receiving station 200 is held in a feedback information accumulator 221 for a predetermined time period, and is outputted to a reception weight generating section 208 to generate a reception weight. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術の分野】
本発明は多入力多出力伝搬路信号伝送装置及び受信局に関する。
【０００２】
【従来の技術】
近年、図８に示すような多入力多出力伝搬路信号伝送装置が提案されている。
送信局１００は送信信号を生成する送信信号生成部１０１、＃１〜＃Ｋの送信信号分割部１０２、＃１〜＃Ｋの送信処理部１０３、＃１〜＃Ｎの送信アンテナ１０５を備えている。そして各送信処理部１０３は、送信信号変調部１１１、乗算部１１１２、既知シンボル付加部１１３から構成されている。
【０００３】
他方、受信局２００は＃１〜＃Ｌの受信アンテナ２０１、既知シンボル分離部２０２、＃１〜＃Ｋの等化処理部２０３、チャネル推定部２０４、送信ウェイト生成部２８１、送信ウェイト蓄積部２８２、受信ウェイト生成部２８３、受信信号結合部２０９を備えている。そして各等化処理部２０３は、乗算部２１１と受信信号復調部２１２から構成されている。
【０００４】
この提案されている多入力多出力伝搬路信号伝送装置では、送信局１００はフィードバック回線４００の利用により、受信局２００から送信ウェイト情報を信号送信前に受信する。フィードバック情報は受信アンテナ２０１の数Ｌと同じ数の＃１〜＃Ｌの組となっており、＃１〜＃Ｌの各組には送信アンテナ１０５の本数Ｎと同じ数のウェイト情報が含まれている。送信局１００の送信信号分割部１０２では、受信局２００からフィードバックされた送信ウェイト情報を参照し、送信ウェイト情報が全て０でない組の数Ｋと同じ数の系列＃１〜＃Ｋに送信信号を分割する。分割された＃１〜＃Ｋの各送信信号系列は、それぞれ送信信号変調部１１１で変調され、乗算部１１２で対応する送信ウェイト情報と乗算され、受信局２００側で等化処理を行うために用いられる既知シンボルを付加される。各送信信号系列は対応する送信アンテナ１０５毎に加算され、伝搬路３００に送信される。
【０００５】
いま、Ｋ個に分割された送信信号系列（ここでは、「ストリーム」と呼ぶ）のうちｋ番目のストリームをＳ_ｋ（ｔ）、送信アンテナ本数をＮ、ｋ番目のストリームに対応する送信ウェイトベクトル（Ｎ×１列）をＷ_Ｔｋとすると、多重化された送信信号ベクトルＸ（ｔ）は、
【数１】

となる。
【０００６】
受信局２００では、無線伝搬路３００によって歪んだ送信信号が受信される。
送信信号系列の歪の様子は伝搬路３００自体の形状と、各送受信アンテナ１０５、２０１の位置関係で決定される。
【０００７】
いま、伝搬路３００は各チャネルにおいて遅延波の影響が無視できるような一様フェージングチャネルを想定する。このとき、既知シンボルを用いて、チャネル推定部２０４において各送受信間の伝搬路特性を推定することで、この伝搬路特性は、以下のチャネル行列Ａによって示される。ただし、Ｌは受信アンテナ本数とする。
【０００８】
【数２】

各受信アンテナ２０１で受信された受信信号ｒ（ｔ）は、ノイズベクトルをｎ（ｔ）とすると、
【数３】

のように示される。
【０００９】
各受信アンテナ２０１で受信された信号は、既知シンボル分離部２０２において既知シンボルと送信情報シンボルとに分離され、送信情報シンボルは＃１〜＃Ｋの各送信信号系列と同じ数Ｋの等化処理部２０３に入力される。既知シンボルはチャネル推定部２０４に入力される。チャネル推定部２０４は、各送受信アンテナ１０５、２０１間の伝搬路特性を推定し、チャネル推定情報を出力する。
【００１０】
受信局２００の送信ウェイト生成部２８１では、チャネル推定情報を用いて送信ウェイト情報を生成する。この送信ウェイト生成には通常、固有値演算や特異値演算を用いる。具体的には、（４）式のようにチャネル相間行列Ａ^ＨＡの固有値分解を行うと、以下の関係を満たすＫ個（Ｋ＝ｍｉｎ（Ｎ，Ｌ））の固有ベクトルｅ_ｋが得られる。ただし、Ｈは複素転置を示している。
【００１１】
【数４】

（４）式で、λ_ｉはｉ番目の固有ベクトルに対応する固有値を示す。上記ｅ_ｋを用いてｋ番目のストリームに対する送信ウェイトベクトルを、
【数５】

のように生成する。この時点で生成された送信ウェイトは、フィードバック回線４００を通じて送信局１００へ送信され、次回の送信時に使用される。
【００１２】
送信ウェイト生成部２８１で生成された送信ウェイトは、送信ウェイトがフィードバックされ、信号送信に用いられて受信局２００で受信されるまで各送信ウェイト蓄積部２８２において保持される。その後、蓄積されている送信ウェイトは受信ウェイト生成部２８３に入力される。受信ウェイト生成部２８３では、蓄積されている送信ウェイト情報とチャネル推定部２０４からのチャネル推定値とを用いて受信ウェイト情報を算出する。
【００１３】
この受信ウェイトベクトル（１行×Ｌ列）Ｗ_Ｒｋは、
【数６】

により生成される。
【００１４】
各等化処理部２０３では、乗算部２１１で受信ウェイト生成部２８３からの受信ウェイト情報を受信信号と乗算して合成し、さらに受信信号復調部２１２で復調処理を行う。
【００１５】
ｋ番目のストリームに対する合成後出力ｙ_ｋ（ｔ）は、
【数７】

となる。
【００１６】
そして各等化処理部２０３での復調処理後の＃１〜＃Ｋの受信信号は、受信信号結合部２０９において送信信号分割部１０２の分割法と対応した形で結合され、送信信号系列が得られる。
【００１７】
このように、提案されている多入力多出力伝搬路信号伝送装置では、送受信ウェイト情報を生成して用いることにより、多重化された他のストリームからの干渉を全く受けずに所望のストリームのみを抽出することができる。この結果、周波数利用効率を従来の１ストリームのみを伝送する場合と比較して飛躍的に高めることができるのである。
【００１８】
しかしながら、上述した多入力多出力伝搬路信号伝送装置では、受信局で算出したウェイト情報をフィードバック回線を用いて送信局に通知する際に遅延が生じ、通信路チャネルが変動してしまう。このような変動が発生すれば、通信チャネルと送受信ウェイトの整合性が乱れ、伝送特性の劣化が生じてしまう。
【００１９】
つまり、従来提案されている技術では、送信ウェイトベクトルを生成したときのチャネル行列をＣ、実際に通信を行った際のチャネル行列をＣ′とすると、送信ウェイトベクトルはチャネル行列Ｃに対して生成されているのに対して、受信ウェイトベクトルＷ_Ｒｋは、Ｗ_Ｒｋ＝（Ｃ′ｅ_ｋ）^Ｈのように、Ｃ′に基づいて生成される。このときの受信局における合成後信号ｙ_ｋ（ｔ）は、
【数８】

となる。このときＷ_ＴｋはＣ^ＨＣの固有ベクトルであり、Ｃ′^ＨＣ′の固有値ではないため、他ストリームからの干渉成分を消去できない。この結果、伝送特性の劣化が生じるという問題点があった。
【００２０】
また従来例では、（５），（６）式のようにチャネル推定値を基に固有値計算を行い、現在の伝搬路に整合した形で送受信ウェイト情報を算出して伝送時に用いている。しかし、フィードバック情報はフィードバック回線を用いて伝達される関係上、フィードバック回線の情報速度に応じた遅延の後に通知されるため、遅延の影響を受けずに生成された受信ウェイト情報との整合性が乱れ、伝送容量が劣化する事態が起こる問題点があった。
【００２１】
【非特許文献１】
宮下、西村、大鐘、小川、鷹取、長著、「ＭＩＭＯチャネルにおける固有ビーム空間分割多重（Ｅ−ＳＤＭ）方式」、電子情報通信学会技報、ＲＣＳ２００２−５３、２００２年５月。
【００２２】
【非特許文献２】
西村、大鐘、小川、鷹取、長著、「固有ビーム空間分割多重方式におけるチャネル推定誤差を考慮した場合の特性評価」、電子情報通信学会技報、ＲＣＳ２００２−９４、２００２年７月。
【００２３】
【発明が解決しようとする課題】
本発明はこのような従来の技術的課題に鑑みてなされたもので、受信ウェイト生成時に加工後の送信ウェイトを用いることにより、送受信ウェイトの整合性を向上させ、伝送特性の劣化を減少させることができる多入力多出力伝搬路信号伝送技術を提供することを目的とする。
【００２４】
【課題を解決するための手段】
請求項１の発明は、複数のアンテナを備えた送信局と複数のアンテナを備えた受信局から成る多入力多出力伝搬路信号伝送装置であって、
前記送信局は、送信信号生成部と、送信信号を複数の系列に分割する送信信号分割部と、分割された各信号系列を変調する送信信号変調部と、前記受信局からのフィードバック回線を通じて通知された加工フィードバック情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記送信信号変調部の変調信号に前記送信ウェイト情報を乗算する送信ウェイト乗算部とを具備し、
前記受信局は、前記送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、通信チャネル情報を入力し、フィードバック情報を生成するフィードバック情報生成部と、前記フィードバック情報を前記フィードバック回線の回線状況に応じて加工して前記加工フィードバック情報を生成し、前記フィードバック回線を通じて前記送信局にフィードバックするフィードバック情報加工部と、前記加工フィードバック情報を一定期間保持し、蓄積された蓄積フィードバック情報を出力するフィードバック情報蓄積部と、前記通信チャネル情報と前記蓄積フィードバック情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、
前記受信局は、前記複数の送信信号系列毎の前記受信信号復調部からの出力を前記送信信号分割部に対応して結合する受信信号結合部を具備することを特徴とするものである。
【００２５】
請求項２の発明は、多入力多出力伝搬路信号伝送に用いられる、複数のアンテナを備えた受信局であって、送信局からの送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、通信チャネル情報を入力し、フィードバック情報を生成するフィードバック情報生成部と、前記フィードバック情報をフィードバック回線の回線状況に応じて加工して加工フィードバック情報を生成し、前記送信局に前記フィードバック回線を通じてフィードバックするフィードバック情報加工部と、前記加工フィードバック情報を一定期間保持し、蓄積された蓄積フィードバック情報を出力するフィードバック情報蓄積部と、前記通信チャネル情報と前記蓄積フィードバック情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、前記複数の送信信号系列毎の前記受信信号復調部からの出力を前記送信局側の送信信号分割法と対応して結合する受信信号結合部を具備することを特徴とするものである。
【００２６】
請求項１の発明の多入力多出力伝搬路信号伝送装置、請求項２の発明の受信局では、送信局側において、送信信号を複数の系列に分割し、分割された各信号系列を変調し、受信局側からのフィードバック回線を通じて通知された加工フィードバック情報を用いて生成された送信ウェイト情報をこの変調信号に乗算し、複数のアンテナから伝搬路に送信する。
【００２７】
受信局側においては、送信局の送信信号を複数のアンテナにて受信し、受信信号から通信チャネル情報を推定し、この通信チャネル情報からフィードバック情報を生成し、さらにフィードバック情報をフィードバック回線の回線状況に応じて加工して加工フィードバック情報を生成し、フィードバック回線を通じて送信局側にこの加工フィードバック情報をフィードバックする。また加工フィードバック情報を一定期間保持し、蓄積された蓄積フィードバック情報と前記通信チャネル情報とを用いて受信ウェイト情報を生成し、複数の信号系列毎に受信信号にこの受信ウェイト情報を乗算し、複数の送信信号系列毎に受信信号を復調する。そして送信信号系列毎の復調信号を送信局側の送信信号分割部に対応して結合し、元の送信信号を得て出力する。
【００２８】
これにより、多入力多出力伝搬路信号伝送において、送信ウェイトのフィードバックに伴う加工処理による送信ウェイトと受信ウェイトとの不整合性を低減し、伝送特性の劣化を低減する。
【００２９】
請求項３の発明は、複数のアンテナを備えた送信局と複数のアンテナを備えた受信局から成る多入力多出力伝搬路信号伝送装置であって、
前記送信局は、送信信号生成部と、前記送信信号を複数の信号系列に分割する送信信号分割部と、分割された各送信信号系列を変調する送信信号変調部と、前記送信信号変調部の変調信号に前記受信局からのフィードバック回線を通じて通知された量子化送信ウェイト情報を乗算する送信ウェイト乗算部とを具備し、
前記受信局は、前記送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記送信ウェイト情報に量子化処理を施して前記量子化送信ウェイト情報を生成し、前記フィードバック回線を通じて前記送信局へフィードバックする送信ウェイト量子化部と、前記量子化送信ウェイト情報を一定期間保持し、蓄積された量子化送信ウェイトを出力する送信ウェイト蓄積部と、前記通信チャネル情報と前記送信ウェイト蓄積部の蓄積された量子化送信ウェイト情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、
前記受信局は、前記複数の送信信号系列毎の前記受信信号復調部からの出力を前記送信信号分割部に対応して結合する受信信号結合部を具備することを特徴とするものである。
【００３０】
請求項４の発明は、多入力多出力伝搬路信号伝送に用いられる、複数のアンテナを備えた受信局であって、送信局からの送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記送信ウェイト情報に量子化処理を施して量子化送信ウェイト情報を生成し、フィードバック回線を通じて前記送信局へフィードバックする送信ウェイト量子化部と、前記量子化送信ウェイト情報を一定期間保持し、蓄積された量子化送信ウェイト情報を出力する送信ウェイト送信ウェイト蓄積部と、前記通信チャネル情報と前記送信ウェイト蓄積部の蓄積された量子化送信ウェイト情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、前記複数の送信信号系列毎の前記受信信号復調部からの出力を結合して元の送信信号を復元する受信信号結合部を具備することを特徴とするものである。
【００３１】
請求項３の発明の多入力多出力伝搬路信号伝送装置、請求項４の発明の受信局では、送信局側において、送信信号を複数の信号系列に分割し、分割された各送信信号系列を変調し、受信局側からフィードバック回線を通じて通知された量子化送信ウェイト情報をこの変調信号に乗算し、複数のアンテナを通じて伝搬路に送信する。
【００３２】
受信局側においては、送信局からの送信信号を複数のアンテナで受信し、受信信号から通信チャネル情報を推定し、この通信チャネル情報を用いて送信ウェイト情報を生成し、さらに送信ウェイト情報に量子化処理を施して量子化送信ウェイト情報を生成し、フィードバック回線を通じて送信局側へフィードバックする。これと共に、量子化送信ウェイト情報を一定期間保持し、通信チャネル情報と蓄積された量子化送信ウェイト情報とを用いて受信ウェイト情報を生成し、複数の信号系列毎に受信信号にこの受信ウェイト情報を乗算し、複数の送信信号系列毎に受信信号を復調する。そして送信信号系列毎の復調信号を送信局側の送信信号分割部に対応して結合し、元の送信信号を得て出力する。
【００３３】
これにより、多入力多出力伝搬路信号伝送において、送信ウェイトのフィードバックに伴う遅延による送信ウェイトと受信ウェイトとの不整合性を低減し、伝送特性の劣化を低減する。
【００３４】
請求項５の発明は、複数のアンテナを備えた送信局と複数のアンテナを備えた受信局から成る多入力多出力伝搬路信号伝送装置であって、
前記送信局は、送信信号生成部と、送信信号を複数の系列に分割する送信信号分割部と、分割された各信号系列を変調する送信信号変調部と、前記受信局からのフィードバック回線を通じて通知された量子化通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記送信信号変調部の変調信号に前記送信ウェイト情報を乗算する送信ウェイト乗算部とを具備し、
前記受信局は、前記送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、前記通信チャネル情報に量子化処理を施して前記量子化通信チャネル情報を生成し、前記フィードバック回線を通じて前記送信局にフィードバックする通信チャネル量子化部と、前記量子化通信チャネル情報を一定期間保持し、蓄積された量子化通信チャネル情報を出力するチャネル蓄積部と、前記チャネル蓄積部の蓄積された量子化通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記チャネル推定部の出力する通信チャネル情報と前記送信ウェイト情報とを用いて受信ウェイトを生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、
前記受信局は、前記複数の送信信号系列毎の前記受信信号復調部からの出力を前記送信信号分割部に対応して結合する受信信号結合部を具備することを特徴とするものである。
【００３５】
請求項６の発明は、多入力多出力伝搬路信号伝送に用いられる、複数のアンテナを備えた受信局であって、送信局からの送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、前記通信チャネル情報に量子化処理を施して量子化通信チャネル情報を生成し、フィードバック回線を通じて前記送信局にフィードバックする通信チャネル量子化部と、前記量子化通信チャネル情報を一定期間保持し、蓄積された量子化通信チャネル情報を出力するチャネル蓄積部と、前記チャネル蓄積部の蓄積された量子化通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記チャネル推定部の出力する通信チャネル情報と前記送信ウェイト情報とを用いて受信ウェイトを生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、前記複数の送信信号系列毎の前記受信信号復調部からの出力を結合して元の送信信号を復元する受信信号結合部を具備することを特徴とするものである。
【００３６】
請求項５の発明の多入力多出力伝搬路信号伝送装置、請求項６の発明の受信局では、送信局側において、送信信号を複数の系列に分割し、分割された各信号系列を変調し、受信局側からのフィードバック回線を通じて通知された量子化通信チャネル情報を用いて生成された送信ウェイト情報をこの変調信号に乗算し、複数のアンテナを通じて伝搬路に送信する。
【００３７】
受信局側においては、送信局からの送信信号を複数のアンテナで受信し、受信信号から通信チャネル情報を推定し、この通信チャネル情報に量子化処理を施して量子化通信チャネル情報を生成し、フィードバック回線を通じて送信局側にフィードバックする。これと共に、量子化通信チャネル情報を一定期間保持し、蓄積された量子化通信チャネル情報を用いて送信ウェイト情報を生成し、前記通信チャネル情報とこの送信ウェイト情報とを用いて受信ウェイトを生成し、複数の信号系列毎に受信信号にこの受信ウェイト情報を乗算し、複数の送信信号系列毎に受信信号を復調する。そして送信信号系列毎の復調信号を送信局側の送信信号分割部に対応して結合し、元の送信信号を得て出力する。
【００３８】
これにより、多入力多出力伝搬路信号伝送において、送信ウェイトのフィードバックに伴う遅延による送信ウェイトと受信ウェイトとの不整合性を低減し、伝送特性の劣化を低減する。
【００３９】
請求項７の発明は、複数のアンテナを備えた送信局と複数のアンテナを備えた受信局から成る多入力多出力伝搬路信号伝送装置であって、
前記送信局は、送信信号生成部と、前記送信信号を複数の信号系列に分割する送信信号分割部と、分割された各送信信号系列を変調する送信信号変調部と、前記送信信号変調部の変調信号に前記受信局からのフィードバック回線を通じて通知された補正送信ウェイト情報を乗算する送信ウェイト乗算部とを具備し、
前記受信局は、前記送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記送信ウェイト生成部が過去に出力した前記送信ウェイト情報を保存する送信ウェイト保存部と、前記送信ウェイト保存部に保存された過去の送信ウェイト情報とあらかじめ与えられているフィードバックに伴う遅延時間情報を用いて前記送信ウェイト生成部の出力する送信ウェイト情報を補正して前記補正送信ウェイト情報を生成し、前記送信局に前記フィードバック回線を通じてフィードバックする送信ウェイト補正部と、前記送信ウェイト補正部からの補正送信ウェイト情報を一定期間保持し、蓄積された補正送信ウェイト情報を出力する送信ウェイト蓄積部と、前記通信チャネル情報と前記送信ウェイト蓄積部の蓄積された補正送信ウェイト情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、
前記受信局は、前記複数の送信信号系列毎の前記受信信号復調部からの出力を前記送信信号分割部に対応して結合する受信信号結合部を具備することを特徴とするものである。
【００４０】
請求項８の発明は、多入力多出力伝搬路信号伝送に用いられる、複数のアンテナを備えた受信局であって、送信局からの送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記送信ウェイト生成部が過去に出力した前記送信ウェイト情報を保存する送信ウェイト保存部と、前記送信ウェイト保存部に保存された過去の送信ウェイト情報とあらかじめ与えられているフィードバックに伴う遅延時間情報を用いて前記送信ウェイト生成部の出力する送信ウェイト情報を補正して補正送信ウェイト情報を生成し、前記送信局にフィードバック回線を通じてフィードバックする送信ウェイト補正部と、前記送信ウェイト補正部からの補正送信ウェイト情報を一定期間保持し、蓄積された補正送信ウェイト情報を出力する送信ウェイト蓄積部と、前記通信チャネル情報と前記送信ウェイト蓄積部の蓄積された補正送信ウェイト情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、前記複数の送信信号系列毎の前記受信信号復調部からの出力を結合して元の送信信号を復元する受信信号結合部を具備することを特徴とするものである。
【００４１】
請求項７の発明の多入力多出力伝搬路信号伝送装置、請求項８の発明の受信局では、送信局側において、送信信号を複数の信号系列に分割し、分割された各送信信号系列を変調し、受信局側からのフィードバック回線を通じて通知された補正送信ウェイト情報をこの変調信号に乗算し、複数のアンテナを通じて伝搬路に送信する。
【００４２】
受信局側においては、送信局からの送信信号を複数のアンテナで受信し、受信信号から通信チャネル情報を推定し、この通信チャネル情報を用いて送信ウェイト情報を生成する。そして、保存されている過去の送信ウェイト情報とあらかじめ与えられているフィードバックに伴う遅延時間情報を用いて、新たに生成された送信ウェイト情報を補正して補正送信ウェイト情報を生成し、送信局側にフィードバック回線を通じてフィードバックする。これと共に、補正送信ウェイト情報を一定期間保持し、蓄積された補正送信ウェイト情報と前記通信チャネル情報とを用いて受信ウェイト情報を生成し、複数の信号系列毎に受信信号にこの受信ウェイト情報を乗算し、複数の送信信号系列毎に受信信号を復調する。そして送信信号系列毎の復調信号を送信局側の送信信号分割部に対応して結合し、元の送信信号を得て出力する。
【００４３】
これにより、多入力多出力伝搬路信号伝送において、送信ウェイト補正時の誤差による送信ウェイトと受信ウェイトとの不整合性を低減し、伝送特性の劣化を低減する。
【００４４】
請求項９の発明は、複数のアンテナを備えた送信局と複数のアンテナを備えた受信局から成る多入力多出力伝搬路信号伝送装置であって、
前記送信局は、送信信号生成部と、送信信号を複数の系列に分割する送信信号分割部と、分割された各信号系列を変調する送信信号変調部と、前記受信局からのフィードバック回線を通じて通知された補正通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部と、前記送信信号変調部の変調信号に前記送信ウェイト情報を乗算する送信ウェイト乗算部とを具備し、
前記受信局は、前記送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、前記チャネル推定部が過去に出力した前記通信チャネル情報を保存するチャネル情報保存部と、前記チャネル情報保存部に保存された過去の通信チャネル情報とあらかじめ与えられているフィードバックに伴う遅延時間情報を用いて前記通信チャネル情報を補正して前記補正通信チャネル情報を生成し、前記フィードバック回線を通じて前記送信局にフィードバックするチャネル情報補正部と、前記補正通信チャネル情報を一定期間保持し、蓄積された補正通信チャネル情報を出力するチャネル蓄積部と、前記チャネル蓄積部の蓄積された補正通信チャネル情報を入力し、送信ウェイト情報を生成する送信ウェイト生成部と、前記送信ウェイト情報を用いて受信ウェイトを生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、
前記受信局は、前記複数の送信信号系列毎の前記受信信号復調部からの出力を前記送信信号分割部に対応して結合する受信信号結合部を具備することを特徴とするものである。
【００４５】
請求項１０の発明は、多入力多出力伝搬路信号伝送に用いられる、複数のアンテナを備えた受信局であって、送信局からの送信信号を受信する複数のアンテナと、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部と、前記チャネル推定部が過去に出力した前記通信チャネル情報を保存するチャネル情報保存部と、前記チャネル情報保存部に保存された過去の通信チャネル情報とあらかじめ与えられているフィードバックに伴う遅延時間情報を用いて前記通信チャネル情報を補正して補正通信チャネル情報を生成し、フィードバック回線を通じて前記送信局にフィードバックするチャネル情報補正部と、前記補正通信チャネル情報を一定期間保持し、蓄積された補正通信チャネル情報を出力するチャネル蓄積部と、前記チャネル蓄積部の蓄積された補正通信チャネル情報を入力し、送信ウェイト情報を生成する送信ウェイト生成部と、前記送信ウェイト情報を用いて受信ウェイトを生成する受信ウェイト生成部と、複数の信号系列毎に前記受信信号に前記受信ウェイト情報を乗算する受信ウェイト乗算部と、前記複数の信号系列毎に前記受信信号を復調する受信信号復調部とを具備し、かつ、前記複数の送信信号系列毎の前記受信信号復調部からの出力を結合して元の送信信号を復元する受信信号結合部を具備することを特徴とするものである。
【００４６】
請求項９の発明の多入力多出力伝搬路信号伝送装置、請求項１０の発明の受信局では、送信局側においては、送信信号を複数の系列に分割し、分割された各信号系列を変調し、受信局側からのフィードバック回線を通じて通知された補正通信チャネル情報を用いて生成された送信ウェイト情報をこの変調信号に乗算し、複数のアンテナを通じて伝搬路に送信する。
【００４７】
受信局側においては、送信局からの送信信号を複数のアンテナで受信し、受信信号から通信チャネル情報を推定し、チャネル情報保存部に保存されている過去の通信チャネル情報とあらかじめ与えられているフィードバックに伴う遅延時間情報を用いて新たに得た通信チャネル情報を補正して補正通信チャネル情報を生成し、フィードバック回線を通じて送信局側にフィードバックする。また、補正通信チャネル情報を一定期間保持し、蓄積された補正通信チャネル情報を用いて送信ウェイト情報を算出し、さらに送信ウェイト情報を用いて受信ウェイトを算出し、複数の信号系列毎に受信信号にこの受信ウェイト情報を乗算し、複数の送信信号系列毎に受信信号を復調する。そして送信信号系列毎の復調信号を送信局側の送信信号分割部に対応して結合し、元の送信信号を得て出力する。
【００４８】
これにより、多入力多出力伝搬路信号伝送において、送信ウェイトのフィードバックに伴う遅延による送信ウェイトと受信ウェイトとの不整合性を低減し、伝送特性の劣化を低減する。
【００４９】
【発明の実施の形態】
以下、本発明の実施の形態を図に基づいて詳説する。
【００５０】
［第１の実施の形態］図１に、本発明の第１の実施の形態の多入力多出力伝搬路信号伝送装置を示す。本実施の形態の多入力多出力伝搬路信号伝送装置は、大きく分けて、送信局１００、受信局２００、伝搬路３００の３つから構成されている。
【００５１】
送信局１００は送信信号を生成する送信信号生成部１０１、＃１〜＃Ｋの送信信号分割部１０２、＃１〜＃Ｋの送信処理部１０３、＃１〜＃Ｎの加算部１０４、＃１〜＃Ｎの送信アンテナ１０５、送信ウェイト生成部１０６を備えている。そして各送信処理部１０３は、送信信号変調部１１１、乗算部１１２、既知シンボル付加部１１１３から構成されている。
【００５２】
他方、受信局２００は＃１〜＃Ｌの受信アンテナ２０１、既知シンボル分離部２０２、＃１〜＃Ｋの等化処理部２０３、チャネル推定部２０４、フィードバック情報生成部２０５、フィードバック情報加工部２０６、フィードバック情報蓄積部２０７、受信ウェイト生成部２０８、受信信号結合部２０９を備えている。
そして各等化処理部２０３は、乗算部２１１と受信信号復調部２１２から構成されている。
【００５３】
本実施の形態の多入力多出力伝搬路信号伝送装置では、送信局１００はフィードバック回線４００の利用により、受信局２００からフィードバック情報を受信し、送信ウェイト生成部１０６によって送信ウェイト情報を生成する。フィードバック情報は受信アンテナ２０１の数Ｌと同じ数の＃１〜＃Ｌの組となっており、＃１〜＃Ｌの各組には送信アンテナ１０２の本数Ｎと同じ数のウェイト情報が含まれている。
【００５４】
送信局１００の送信ウェイト生成部１０６は、受信局２００からフィードバックされた情報に基づき生成された送信ウェイト情報を生成する。この送信ウェイト情報の生成には通常、固有値演算や特異値演算を用いる。具体的にはチャネル行列をＡとすると、チャネル相関行列Ａ^ＨＡの固有値分解を行うことで以下の関係を満たすＫ個（Ｋ＝ｍｉｎ（Ｎ，Ｌ））の固有ベクトルｅ_ｋを得る。
【００５５】
【数９】

ただし、記号Ｈは複素転置を示している。また、λ_ｉはｉ番目の固有ベクトルに対応する固有値を示す。
【００５６】
上記固有ベクトルｅ_ｋを用いてｋ番目のストリームに対する送信ウェイトベクトルを
【数１０】

のように生成する。
【００５７】
送信局１００の送信信号分割部１０２では送信ウェイト情報を参照し、送信ウェイト情報が全て０でない組の数と同じ数の系列に送信信号を分割する。分割された各送信信号系列は、それぞれ送信信号変調部１１１で変調され、対応する送信ウェイトと乗算され、受信局２００側で等化処理を行うために用いられる既知シンボルを付加される。各送信信号系列は加算部１０４にて対応する送信アンテナ１０５毎に加算され、送信アンテナ１０５から伝搬路３００に送信される。いま、Ｋ個に分割された送信信号系列（ストリーム）のうちｋ番目のストリームをＳ_ｋ（ｔ）、送信アンテナ本数をＮ、ｋ番目のストリームに対応する送信ウェイトベクトル（Ｎ行×１列）をＷ_Ｔｋとすると、多重化された送信信号ベクトルＸ（ｔ）は、
【数１１】

となる。
【００５８】
送信された信号は無線伝搬路３００によって歪んだ後、受信局２００で受信される。送信信号系列の歪の様子は伝搬路３００自体の形状と、各送受信アンテナ１０５，２０１の位置関係で決定される。いま、伝搬路３００は各チャネルにおいて遅延波の影響が無視できるような一様フェージングチャネルを想定する。
【００５９】
受信局２００では、受信信号が既知シンボル分割部２０２で既知シンボルと送信情報シンボルとに分離される。送信情報シンボルは各送信信号系列と同じ数の等化処理部２０３に入力され、既知シンボルはチャネル推定部２０４に入力される。既知シンボルを用いてチャネル推定部２０４において各送受信間の伝搬路特性を推定し、通信チャネル情報を出力する。
【００６０】
この伝搬路特性は以下のチャネル行列Ａによって示される。ただし、Ｌは受信アンテナ２０１の本数とする。
【００６１】
【数１２】

各受信アンテナ２０１で受信された受信信号ｒ（ｔ）は、ノイズベクトルをｎ（ｔ）とすると、
【数１３】

のように示される。
【００６２】
チャネル推定部２０４の出力する通信チャネル情報を用いて、フィードバック情報生成部２０５においてフィードバック情報が生成される。このフィードバック情報として送信ウェイト情報を用いる場合は、フィードバック情報生成部２０５にて上述した送信ウェイト生成部１０６と同様の処理が行われる。したがって、この場合、送信局１００側には送信ウェイト生成部１０６が不要となる。他方、フィードバック情報として通信チャネル情報をフィードバックする場合、フィードバック情報生成部２０５はスルーとなる。
【００６３】
生成されたフィードバック情報はフィードバック情報加工部２０６とフィードバック情報蓄積部２０７に入力される。フィードバック情報加工部２０６ではフィードバック情報に対して、フィードバック回線４００の帯域、フィードバック情報量等に応じた加工を施した後、加工フィードバック情報を出力する。この加工フィードバック情報はフィードバック回線４００を通じて送信局１００に通知される。フィードバック情報蓄積部２０７では、加工フィードバック情報が送信局１００に通知され、通知情報を用いて送信された信号が受信局２００で受信されるまでの一定期間フィードバック情報を保持する。フィードバック情報生成部２０５がスルーだった場合は、保持終了後に送信局１００側の送信ウェイト生成部１０６と同様の処理が施され、送信ウェイト情報が蓄積フィードバック情報として出力される。
【００６４】
前記一定期間が経過した後、フィードバック情報蓄積部２０７から蓄積フィードバック情報が受信ウェイト生成部２０８へ出力される。受信ウェイト生成部２０８では、通信チャネル情報と蓄積フィードバック情報を用いて受信ウェイト情報を生成する。このとき、受信ウェイトベクトル（１行×Ｌ列）Ｗ_Ｒｋは、
【数１４】

のように生成される。
【００６５】
生成された受信ウェイト情報は受信信号と乗算される。ｋ番目のストリームに対する合成後出力ｙ_ｋ（ｔ）は、
【数１５】

となる。
【００６６】
このように送受信ウェイトを生成して用いることにより、多重化された他のストリームからの干渉を全く受けずに所望のストリームのみを抽出することができる。この結果、本実施の形態の多入力多出力伝搬路信号伝送装置では、周波数利用効率を従来の１ストリームのみを伝送する場合と比較して飛躍的に高めることが可能となる。
【００６７】
［第２の実施の形態］次に、本発明の第２の実施の形態の多入力多出力伝搬路信号伝送装置について、図２を用いて説明する。
【００６８】
図１に示した第１の実施の形態の多入力多出力伝搬路信号伝送装置では、フィードバック情報をフィードバック回線を用いて送信局に通知する際、フィードバック回線の帯域、フィードバック情報量に応じた加工による劣化が生じことがあり得る。この結果、送受信ウェイト間の整合性が乱れ、伝送特性の劣化が生じてしまう場合がある。つまり、加工前の送信ウェイト情報、加工後の送信ウェイト情報それぞれを
【数１６】

とすると、第１の実施の形態の技術では、受信ウェイトを
【数１７】

として生成する。
【００６９】
このときの受信局２００における合成後信号ｙ_ｋ（ｔ）は、
【数１８】

となる。このとき、
【数１９】

の加工前の送信ウェイト情報と加工後の送信ウェイト情報との間には加工に伴う誤差が生じているために送受信ウェイト間の整合性が乱れることがあり、その場合には他ストリームからの干渉成分を十分消去できず、この結果として伝送特性の劣化が生じ得ることが予想される。
【００７０】
図２に示した本実施の形態の多入力多出力伝搬路信号伝送装置において、図１に示した第１の実施の形態の多入力多出力伝搬路信号伝送装置と共通する構成要素については同一の符号を付して示している。第１の実施の形態の多入力多出力伝搬路信号伝送装置では、受信局２００において受信ウェイトの生成時に加工を施さない状態のフィードバック情報を用いていたのに対して、本実施の形態では、受信局２００のフィードバック情報加工部２０６において加工した後の加工フィードバック情報をフィードバック情報蓄積部２２１で一定時間保持し、受信ウェイト生成部２０８に出力し、受信ウェイトを生成するようにした点を特徴とする。
【００７１】
【表１】

表１に第１の実施の形態と第２の実施の形態との関係を示す。第１の実施の形態では、（１０）式のようにチャネル推定値を基に固有値計算を行い、現在の伝搬路に整合した形で送受信ウェイトを算出して伝送時に用いているが、フィードバック情報はフィードバック回線を用いて伝達される関係上、フィードバック回線の情報速度に応じた加工処理が施されるため、加工処理の影響を受けずに生成された受信ウェイトとの整合性が乱れ、伝送容量が劣化するといった事態が起こり得た。
【００７２】
これに対して、本実施の形態では送信ウェイトと受信ウェイトとの整合性を保持することを目的に、フィードバック情報に加工を施した後の加工フィードバック情報を用いて受信ウェイトを生成する。これにより、送信ウェイトのフィードバックに伴う加工処理による送信ウェイトと受信ウェイトとの不整合性を低減することができる。つまり、加工前のフィードバック情報を用いて生成した送信ウェイト情報を
【数２０】

とし、加工後のフィードバック情報を用いて生成した加工送信ウェイト情報を
【数２１】

とすると、第１の実施の形態の方法では受信ウェイトを
【数２２】

として生成していたところを、
【数２３】

として生成することになる。このときの合成後信号ｙ_ｋ（ｔ）は、
【数２４】

となる。
【００７３】
以上の動作により、本第２の実施の形態による多入力多出力伝搬路信号伝送装置では、フィードバック時の加工による誤差が生じた際の影響を低減することが可能となり、伝送特性の劣化を低減することができる。
【００７４】
［第３の実施の形態］図３に本発明の第３の実施の形態を示す。本実施の形態ではフィードバックに伴って生じる誤差として、量子化に伴う誤差を低減することを目的としている。図１に示した第１の実施の形態の技術では受信ウェイトの生成時に量子化を施さない状態の送信ウェイト情報を用いていたのに対して、本実施の形態では、送信ウェイト情報を送信ウェイト量子化部において量子化した後の量子化送信ウェイト情報を用いて受信ウェイト生成を行う点が異なる。
【００７５】
図３に示すように本実施の形態の多入力多出力伝搬路信号伝送装置は、複数のアンテナ１０５を備えた送信局１００と複数のアンテナ２０１を備えた受信局２００と、無線伝搬路３００から構成される。
【００７６】
送信局１００は図１の第１の実施の形態の送信局とほぼ同様の構成であるが、送信ウェイト生成部を備えておらず、受信局２００側からフィードバックされる量子化送信ウェイト情報を利用するようにしている。
【００７７】
一方、受信局２００は、複数の信号系列毎のアンテナ２０１による受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部２０４と、通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部２３１と、送信ウェイト情報に量子化処理を施して量子化送信ウェイト情報を生成し、フィードバック回線４００を通じて送信局１００へフィードバックする送信ウェイト量子化部２３２と、量子化送信ウェイト情報を一定期間保持し、蓄積された量子化送信ウェイトを出力する送信ウェイト蓄積部２３３と、通信チャネル情報と送信ウェイト蓄積部２３３の蓄積された量子化送信ウェイト情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部２３４と、受信信号に受信ウェイト情報を乗算する受信ウェイト乗算部２１１と、受信信号を復調する受信信号復調部２１２を備えている。受信局２００はさらに、複数の送信信号系列毎の等化処理部２０３の受信信号復調部２１２それぞれからの復調出力を送信局１００側の送信信号分割部１０２の分割法と対応して結合して受信信号を出力する受信信号結合部２０９を備えている。
【００７８】
第１の実施の形態では、（１０）式のようにチャネル推定値を基に固有値計算を行い、現在の伝搬路に整合した形で送受信ウェイトを算出して伝送時に用いたが、送信ウェイト情報はフィードバック回線を用いて伝達される関係上、送信ウェイトはフィードバック回線の情報速度に応じた量子化が施されるため、量子化の影響を受けずに生成された受信ウェイトとの整合性が乱れ、伝送容量が劣化する事態が起こることが予想される。
【００７９】
このような状況に対応するために、本実施の形態では送信ウェイトと受信ウェイトとの整合性を保持することを目的に、送信ウェイト情報に量子化を施した後の量子化送信ウェイト情報を用いて受信ウェイトを生成する。これにより、送信ウェイトのフィードバックに伴う遅延による送信ウェイトと受信ウェイトとの不整合性を低減することができる。
【００８０】
つまり、量子化前の送信ウェイト情報、量子化後の送信ウェイト情報それぞれを
【数２５】

とすると、第１の実施の形態では受信ウェイトを
【数２６】

として生成していたところを、
【数２７】

として生成することになる。このときの合成後信号ｙ_ｋ（ｔ）は、
【数２８】

となる。
【００８１】
以上の動作により、本実施の形態による多入力多出力伝搬路信号伝送では、フィードバックによる量子化誤差が生じた際の影響を低減することが可能となり、伝送特性の劣化を低減することができる。
【００８２】
［第４の実施の形態］図４に本発明の第４の実施の形態を示す。図３に示した第３の実施の形態では受信局２００で算出した送信ウェイト情報をフィードバック回線４００によって送信局１００に通知していたのに対して、本実施の形態では量子化通信チャネル情報を送信局１００にフィードバック回線４００を用いて通知し、送信局１００側で送信ウェイト情報を生成するようにしたことを特徴とする。
【００８３】
本実施の形態の多入力多出力伝搬路信号伝送装置は、複数のアンテナ１０５を備えた送信局１００と複数のアンテナ２０１を備えた受信局２００と、無線伝搬路３００から構成される。なお、図１に示した第１のの実施の形態と共通する構成要素には同一の符号を付している。
【００８４】
送信局１００は、送信信号生成部１０１と、送信信号を複数の系列に分割する送信信号分割部１０２と、分割された各信号系列を変調する送信信号変調部１１１と、受信局２００からのフィードバック回線４００を通じて通知された量子化通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部１２１と、送信信号変調部１１１の変調信号に送信ウェイト情報を乗算する送信ウェイト乗算部１１２と、既知シンボル付加部１１３と、加算部１０４を備えている。
【００８５】
一方、受信局２００は、複数の信号系列毎のアンテナ２０１による受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部２０４と、通信チャネル情報に量子化処理を施して量子化通信チャネル情報を生成し、フィードバック回線４００を通じて送信局１００にフィードバックする通信チャネル量子化部２４１と、量子化通信チャネル情報を一定期間保持し、蓄積された量子化通信チャネル情報を出力するチャネル蓄積部２４２と、チャネル蓄積部２４２の蓄積された量子化通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部２４３と、チャネル推定部２０４の出力する通信チャネル情報と送信ウェイト情報とを用いて受信ウェイトを生成する受信ウェイト生成部２４４と、受信信号に受信ウェイト情報を乗算する受信ウェイト乗算部２１１と、受信信号を復調する受信信号復調部２１２を備えている。受信局２００はさらに複数の送信信号系列毎の等化処理部２０３それぞれの受信信号復調部２１２から出力される復調信号を送信局１００側の送信信号分割部１０２の分割法と対応して結合し、受信信号を出力する受信信号結合部２０９を備えている。
【００８６】
このような構成においては、送信ウェイト情報はフィードバック回線の情報速度に応じた量子化が施された通信チャネル情報を用いて生成されるため、量子化の影響を受けずに生成された受信ウェイトとの整合性が乱れ、伝送容量が劣化するといった事態が起こることが予想されるが、このような状況に対応するために、本実施の形態では送信ウェイトと受信ウェイトとの整合性を保持することを目的にして、通信チャネル情報に量子化を施した後の量子化通信チャネル情報を用いて受信ウェイトを生成する。
【００８７】
これにより、本実施の形態による多入力多出力伝搬路信号伝送方式では、送信ウェイトのフィードバックに伴う遅延による送信ウェイトと受信ウェイトとの不整合性を低減することができる。つまり、量子化前の通信チャネル情報、量子化後の送信ウェイト情報をそれぞれ
【数２９】

とすると、送信ウェイトは
【数３０】

の特異値分解若しくは固有値分解を行うことで得られる固有ベクトル
【数３１】

を用いて以下のように表せる。
【００８８】
【数３２】

これに対して第１の実施の形態では受信ウェイトを
【数３３】

として生成していたところを、本実施の形態によれば
【数３４】

として生成することになる。このときの合成後信号ｙ_ｋ（ｔ）は、
【数３５】

となる。
【００８９】
以上の動作により、本実施の形態による多入力多出力伝搬路信号伝送方式では、フィードバックによる量子化誤差が生じた際の影響を低減することが可能となり、伝送特性の劣化を低減することができる。
【００９０】
［第５の実施の形態］図５に本発明の第５の実施の形態を示す。本実施の形態ではフィードバックに伴い生じる誤差として、フィードバック遅延の補償を目的に行うウェイト補正時に生じる補正誤差を問題としている。図１の第１の実施の形態では、（１０）式のようにチャネル推定値を基に固有値計算を行い、現在の伝搬路に整合した形で送受信ウェイトを算出して伝送時に用いているが、送信ウェイト情報はフィードバック回線を用いて伝達される関係上、送信ウェイトはフィードバック回線の情報速度に応じた遅延の後に受信されるため、送信ウェイトと通信チャネルとの整合性が乱れ、伝送容量が劣化するといった事態が起こる。
【００９１】
このような状況に対応するために、フィードバックによる遅延に伴う送信ウェイト及び通信チャネル間の不整合性を低減させることを目的とし、送信ウェイト補正部を用いることができ、その場合、例えば遅延時間情報と送信ウェイト保存部に保存された過去に使用された送信ウェイト情報を基に、一次外挿処理を用いることによって送信ウェイトを補正することが考えられる。上記遅延時間情報は例えば、送信局、受信局それぞれにおいてウェイト生成及び補正に必要な時間と、送信ウェイト情報を受信してから実際の通信に用いられるまでの所要時間を計測することで算出することができる。しかし、遅延時間情報の精度及び送信ウェイト補正時の誤差により送受信ウェイトと通信チャネル間に不整合が発生すると考えられる。
【００９２】
そこで本実施の形態の多入力多出力伝搬路信号伝送装置では、送信ウェイトと受信ウェイトとの整合性を保持することを目的に、送信ウェイト情報に補正を施した後の補正送信ウェイト情報を用いて受信ウェイトを生成するようにしている。
【００９３】
図５を用いて、本実施の形態の多入力多出力伝搬路信号伝送装置の構成を説明する。本実施の形態の多入力多出力伝搬路信号伝送装置は、複数のアンテナ１０５を備えた送信局１００と複数のアンテナ２０１を備えた受信局２００と、無線伝搬路３００から構成される。送信局１００は、図３に示した第３の実施の形態と同様の構成であるので、共通する構成要素に同一の符号を付して示し、その説明は省略する。
【００９４】
一方、受信局２００は、複数の信号系列毎のアンテナ２０１による受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部２０４と、通信チャネル情報を用いて送信ウェイト情報を生成する送信ウェイト生成部２３１と、送信ウェイト生成部２３１が過去に出力した送信ウェイト情報を保存する送信ウェイト保存部２５１と、送信ウェイト保存部２５１に保存された過去の送信ウェイト情報とあらかじめ与えられているフィードバックに伴う遅延時間情報２５３を用いて送信ウェイト生成部２３１の出力する送信ウェイト情報を補正して補正送信ウェイト情報を生成し、送信局１００にフィードバック回線４００を通じてフィードバックする送信ウェイト補正部２５２と、送信ウェイト補正部２５２からの補正送信ウェイト情報を一定期間保持し、蓄積された補正送信ウェイト情報を出力する送信ウェイト蓄積部２３３と、通信チャネル情報と送信ウェイト蓄積部２３３の蓄積された補正送信ウェイト情報とを用いて受信ウェイト情報を生成する受信ウェイト生成部２３４と、受信信号に受信ウェイト情報を乗算する受信ウェイト乗算部２１１と、受信信号を復調する受信信号復調部２１２を備えている。受信局２００はさらに、複数の送信信号系列毎の等化処理部２０３の受信信号復調部２１２それぞれからの復調出力を送信局１００側の送信信号分割部１０２の分割法と対応して結合して受信信号を出力する受信信号結合部２０９を備えている。
【００９５】
以上の構成により、本実施の形態の多入力多出力伝搬路信号伝送装置では、送信ウェイトと受信ウェイトとの整合性を保持することを目的に、受信局２００において送信ウェイト情報に補正を施した後の補正送信ウェイト情報を用いて受信ウェイトを生成する。これにより、本実施の形態による多入力多出力伝搬路信号伝送では、送信ウェイト補正時の誤差による送信ウェイトと受信ウェイトとの不整合性を低減することができる。
【００９６】
つまり、補正前の送信ウェイト情報、補正後の送信ウェイト情報それぞれを
【数３６】

とすると、第１の実施の形態では受信ウェイトを
【数３７】

として生成していたところを、本実施の形態では
【数３８】

として生成することになる。このときの合成後信号ｙ_ｋ（ｔ）は、
【数３９】

となり、補正誤差の影響をも考慮して送受信ウェイト間の整合性を保つことが可能となる。
【００９７】
以上により、本実施の形態による多入力多出力伝搬路信号伝送方式では、フィードバックによる誤差が生じた際の影響を低減することが可能となり、伝送特性の劣化を低減することができる。
【００９８】
［第６の実施の形態］図６に本発明の第６の実施の形態を示す。第５の実施の形態による伝送方式では、受信局で算出した送信ウェイト情報をフィードバック回線によって送信局に通知していたのに対して、本実施の形態では補正通信チャネル情報を送信局にフィードバック回線を用いて通知し、送信局側で送信ウェイト情報を生成する点を特徴とする。
【００９９】
図６を用いて本実施の形態の構成を説明する。本実施の形態の多入力多出力伝搬路信号伝送装置は、複数のアンテナ１０５を備えた送信局１００と複数のアンテナ２０１を備えた受信局２００と、無線伝搬路３００から構成される。
【０１００】
送信局１００は、図２、図４に示した実施の形態とほぼ共通であるが、送信ウェイト生成部１３１は受信局２００からフィードバックされる補正通信チャネル情報を用いて送信ウェイト情報を生成する点が他のものとは異なっている。
【０１０１】
また受信局２００は、複数の信号系列毎に、送信信号を受信する複数のアンテナ２０１と、受信信号から通信チャネル状況を推定し、通信チャネル情報を出力するチャネル推定部２０４と、チャネル推定部２０４が過去に出力した通信チャネル情報を保存するチャネル情報保存部２６１と、チャネル情報保存部２６１に保存された過去の通信チャネル情報とあらかじめ与えられているフィードバックに伴う遅延時間情報２５３を用いて通信チャネル情報を補正して補正通信チャネル情報を生成し、フィードバック回線４００を通じて送信局１００にフィードバックするチャネル情報補正部２６２と、補正通信チャネル情報を一定期間保持し、蓄積された補正通信チャネル情報を出力するチャネル蓄積部２４２と、チャネル蓄積部２４２の蓄積された補正通信チャネル情報を入力し、送信ウェイト情報を生成する送信ウェイト生成部２４３と、送信ウェイト情報を用いて受信ウェイトを生成する受信ウェイト生成部２４４と、受信信号に受信ウェイト情報を乗算する受信ウェイト乗算部２１１と、受信信号を復調する受信信号復調部２１２を備えている。受信局２００はまた、複数の送信信号系列毎の等化処理部２０３の受信信号復調部２１２それぞれからの復調出力を送信局１００側の送信信号分割部１０２の分割法と対応して結合し、受信信号を出力する受信信号結合部２０９を備えている。
【０１０２】
送信ウェイト情報をフィードバック回線４００の情報速度に応じた遅延の影響を受けた通信チャネル情報を用いて生成する場合、遅延の影響を受けずに生成された受信ウェイトとの整合性が乱れ、伝送容量が劣化するといった事態が起こり得る。
【０１０３】
このような状況に対応するために、本実施の形態では、送信ウェイトと受信ウェイトとの整合性を保持することを目的に、通信チャネル情報に補正処理を施した後の補正通信チャネル情報を用いて受信ウェイトを生成する。これにより、本実施の形態では、送信ウェイトのフィードバックに伴う遅延による送信ウェイトと受信ウェイトとの不整合性を低減することができる。
【０１０４】
つまり、補正前の通信チャネル情報、補正後の通信チャネル情報それぞれを
【数４０】

とすると、送信ウェイトは、
【数４１】

の特異値分解若しくは固有値分解を行うことで得られる固有ベクトル
【数４２】

を用いて以下のように表せる。
【０１０５】
【数４３】

これに対して、第１の実施の形態では、受信ウェイトを
【数４４】

として生成していた。このときの合成後信号ｙ_ｋ（ｔ）は、
【数４５】

となる。
【０１０６】
一方、本実施の形態では、
【数４６】

として生成することになる。このときの合成後信号ｙ_ｋ（ｔ）は、
【数４７】

となる。送信ウェイトは
【数４８】

の固有ベクトルであるから、（２４）式の方が不整合性に伴う影響は小さくなる。
【０１０７】
以上の動作により、本実施の形態による多入力多出力伝搬路信号伝送では、フィードバックによる遅延が生じた際の影響を低減することが可能となり、伝送特性の劣化を低減することができる。
【０１０８】
【実施例】
本発明の第３の実施の形態に示す構成での改善効果評価を目的に、計算機シミュレーションを行った。シミュレーション条件を以下に示す。
【０１０９】
送受信アンテナ１０５，２０１の本数は共に４本とし、変調方式はＢＰＳＫ、ＱＰＳＫ、１６ＱＡＭ、６４ＱＡＭを伝搬路品質に応じて適応的に切り替える構成とした。チャネル符号化は行っていない。各送信信号系列は等電力で送信されるものとした。伝搬路３００は各送受信アンテナ間で１波レイリーフェージングを想定し、送信ブランチ間及び受信ブランチ間の相関特性は下記の参考文献のＣａｓｅＩＩを参考に設定した。平均信号電力対雑音電力比は２０ｄＢとした。
【０１１０】
本発明の第１の実施の形態及び第３の実施の形態による伝送方式について、横軸を１フレーム当たりに使用する総量子化ビット数、縦軸を平均スループットとして評価した結果を図７に示す。両方式共に横軸の値が小さくなるほどスループットが減少しているが、第３の実施の形態による伝送方式では第１の実施の形態による伝送方式と比較してより良好な特性が維持できているのが確認できた。
【０１１１】
［参考文献］
“Ｊｏｉｎｔ３ＧＰＰ３ＧＰＰ２ＳｐａｔｉａｌＣｈａｎｎｅｌＭｏｄｅｌｉｎｇＡＨＧＳｔａｔｕｓＲｅｐｏｒｔ”，ＲＡＮ１＃２７，Ｊｕｌｙ２−５，２００２．
【０１１２】
【発明の効果】
以上のように本発明によれば、送受信ウェイトの整合性を考慮してウェイトを設定できるため、フィードバックに伴う量子化による特性の劣化を低減することができ、その結果として、良好な伝送特性を維持することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態の多入力多出力伝搬路信号伝送装置のブロック図。
【図２】本発明の第２の実施の形態の多入力多出力伝搬路信号伝送装置のブロック図。
【図３】本発明の第３の実施の形態の多入力多出力伝搬路信号伝送装置のブロック図。
【図４】本発明の第４の実施の形態の多入力多出力伝搬路信号伝送装置のブロック図。
【図５】本発明の第５の実施の形態の多入力多出力伝搬路信号伝送装置のブロック図。
【図６】本発明の第６の実施の形態の多入力多出力伝搬路信号伝送装置のブロック図。
【図７】本発明の第１の実施の形態による伝送方式と第３の実施の形態による伝送方式との伝送特性を比較するグラフ。
【図８】従来例の多入力多出力伝搬路信号伝送装置のブロック図。
【符号の説明】
１００送信局
１０１送信信号生成部
１０２送信信号分割部
１０３信号処理部
１０４加算部
１０５アンテナ
１０６送信ウェイト生成部
１１１送信信号変調部
１１２送信ウェイト乗算部
１１３既知シンボル付加部
１２１送信ウェイト生成部
１３１送信ウェイト生成部
２００受信局
２０１アンテナ
２０２既知シンボル分離部
２０３等化処理部
２０４チャネル推定部
２０５フィードバック情報生成部
２０６フィードバック情報加工部
２０８受信ウェイト生成部
２０９受信信号結合部
２１１受信ウェイト乗算部
２１２受信信号復調部
２２１フィードバック情報蓄積部
２３１送信ウェイト生成部
２３２送信ウェイト量子化部
２３３送信ウェイト蓄積部
２３４受信ウェイト生成部
２４１通信チャネル量子化部
２４２チャネル蓄積部
２４３送信ウェイト生成部
２４４受信ウェイト生成部
２５１送信ウェイト保存部
２５２送信ウェイト補正部
２５３遅延時間情報
２６１チャネル情報保存部
２６２チャネル情報補正部
３００伝搬路
４００フィードバック回線[0001]
[Field of the Invention]
The present invention relates to a multi-input multi-output propagation path signal transmission apparatus and a receiving station.
[0002]
[Prior art]
In recent years, a multi-input multi-output propagation path signal transmission apparatus as shown in FIG. 8 has been proposed.
The transmission station 100 includes a transmission signal generation unit 101 that generates transmission signals, # 1 to #K transmission signal division units 102, # 1 to #K transmission processing units 103, and # 1 to #N transmission antennas 105. Yes. Each transmission processing unit 103 includes a transmission signal modulation unit 111, a multiplication unit 1112, and a known symbol addition unit 113.
[0003]
On the other hand, the receiving station 200 includes # 1 to #L receiving antennas 201, a known symbol separation unit 202, # 1 to #K equalization processing units 203, a channel estimation unit 204, a transmission weight generation unit 281 and a transmission weight accumulation unit 282. A reception weight generation unit 283 and a reception signal combining unit 209. Each equalization processing unit 203 includes a multiplication unit 211 and a received signal demodulation unit 212.
[0004]
In this proposed multi-input multi-output propagation path signal transmission apparatus, the transmitting station 100 receives transmission weight information from the receiving station 200 before signal transmission by using the feedback line 400. The feedback information is a set of # 1 to #L as many as the number L of the receiving antennas 201, and each set of # 1 to #L includes the same number of weight information as the number N of the transmission antennas 105. ing. The transmission signal division unit 102 of the transmission station 100 refers to the transmission weight information fed back from the reception station 200, and transmits transmission signals to the same number of sequences # 1 to #K as the number K of sets whose transmission weight information is not all zero. To divide. Each of the divided transmission signal sequences # 1 to #K is modulated by the transmission signal modulation unit 111, multiplied by the corresponding transmission weight information by the multiplication unit 112, and is subjected to equalization processing on the receiving station 200 side. A known symbol to be used is added. Each transmission signal sequence is added for each corresponding transmission antenna 105 and transmitted to the propagation path 300.
[0005]
Now, the k-th stream of the transmission signal sequence (herein referred to as “stream”) divided into K pieces is designated as S. _k (T), the number of transmission antennas is N, and the transmission weight vector (N × 1 column) corresponding to the k-th stream is W _Tk Then, the multiplexed transmission signal vector X (t) is
[Expression 1]

It becomes.
[0006]
The receiving station 200 receives a transmission signal distorted by the radio propagation path 300.
The state of distortion of the transmission signal sequence is determined by the shape of the propagation path 300 itself and the positional relationship between the transmission /

reception antennas

105 and 201.
[0007]
Now, it is assumed that the propagation path 300 is a uniform fading channel in which the influence of the delayed wave can be ignored in each channel. At this time, by using the known symbol, the channel estimation unit 204 estimates the channel characteristic between the transmission and reception, and this channel characteristic is represented by the following channel matrix A. However, L is the number of receiving antennas.
[0008]
[Expression 2]

The received signal r (t) received by each receiving antenna 201 has a noise vector n (t).
[Equation 3]

As shown.
[0009]
Signals received by the respective receiving antennas 201 are separated into known symbols and transmission information symbols by a known symbol separation unit 202, and the transmission information symbols are equalized by the same number K as the transmission signal sequences # 1 to #K. Input to the unit 203. The known symbol is input to the channel estimation unit 204. The channel estimation unit 204 estimates channel characteristics between the transmission /

reception antennas

105 and 201 and outputs channel estimation information.
[0010]
The transmission weight generation unit 281 of the receiving station 200 generates transmission weight information using the channel estimation information. For this transmission weight generation, eigenvalue calculation or singular value calculation is usually used. Specifically, the channel interphase matrix A as shown in Equation (4). ^H When eigenvalue decomposition of A is performed, K (K = min (N, L)) eigenvectors e satisfying the following relationship: _k Is obtained. Here, H indicates complex transposition.
[0011]
[Expression 4]

In equation (4), λ _i Indicates an eigenvalue corresponding to the i-th eigenvector. E _k The transmission weight vector for the kth stream using
[Equation 5]

Generate as follows. The transmission weight generated at this time is transmitted to the transmitting station 100 through the feedback line 400 and used at the next transmission.
[0012]
The transmission weight generated by the transmission weight generation unit 281 is held in each transmission weight storage unit 282 until the transmission weight is fed back, used for signal transmission, and received by the receiving station 200. Thereafter, the accumulated transmission weight is input to the reception weight generation unit 283. Reception weight generation section 283 calculates reception weight information using the accumulated transmission weight information and the channel estimation value from channel estimation section 204.
[0013]
This reception weight vector (1 row × L column) W _Rk Is
[Formula 6]

Is generated by
[0014]
In each equalization processing unit 203, the multiplication unit 211 multiplies the reception weight information from the reception weight generation unit 283 by the reception signal and combines them, and the reception signal demodulation unit 212 performs demodulation processing.
[0015]
Post-composition output y for the kth stream _k (T)
[Expression 7]

It becomes.
[0016]
The received signals # 1 to #K after the demodulation processing in each equalization processing unit 203 are combined in a form corresponding to the division method of the transmission signal division unit 102 in the reception signal combination unit 209 to obtain a transmission signal sequence. It is done.
[0017]
In this way, the proposed multi-input multi-output propagation path signal transmission apparatus generates and uses transmission / reception weight information, so that only a desired stream is received without any interference from other multiplexed streams. Can be extracted. As a result, the frequency utilization efficiency can be dramatically improved as compared with the case where only one conventional stream is transmitted.
[0018]
However, in the above-described multi-input multi-output propagation path signal transmission apparatus, a delay occurs when the weight information calculated by the receiving station is notified to the transmitting station using the feedback line, and the communication channel changes. If such a fluctuation occurs, the consistency between the communication channel and the transmission / reception weight is disturbed, and the transmission characteristics are deteriorated.
[0019]
That is, in the conventionally proposed technique, a transmission weight vector is generated for the channel matrix C, where C is the channel matrix when the transmission weight vector is generated and C 'is the channel matrix when the communication is actually performed. The received weight vector W _Rk W _Rk = (C'e _k ) ^H Is generated based on C ′. The combined signal y at the receiving station at this time _k (T)
[Equation 8]

It becomes. At this time W _Tk Is C ^H C's eigenvector, C ' ^H Since it is not an eigenvalue of C ′, interference components from other streams cannot be eliminated. As a result, there has been a problem that transmission characteristics deteriorate.
[0020]
In the conventional example, eigenvalue calculation is performed based on the channel estimation value as shown in equations (5) and (6), and transmission / reception weight information is calculated in a form consistent with the current propagation path and used during transmission. However, because the feedback information is transmitted using the feedback line, it is notified after a delay corresponding to the information speed of the feedback line, so that the consistency with the received weight information generated without being affected by the delay is There was a problem that the transmission capacity deteriorated due to disturbance.
[0021]
[Non-Patent Document 1]
Miyashita, Nishimura, Ogane, Ogawa, Takatori, Nagasaki, “Eigenbeam Space Division Multiplexing (E-SDM) System in MIMO Channel”, IEICE Technical Report, RCS2002-53, May 2002.
[0022]
[Non-Patent Document 2]
Nishimura, Ogane, Ogawa, Takatori, Nagasaki, “Characteristic evaluation in consideration of channel estimation error in eigenbeam space division multiplexing”, IEICE Technical Report, RCS2002-94, July 2002.
[0023]
[Problems to be solved by the invention]
The present invention has been made in view of such a conventional technical problem. By using a transmission weight after processing when generating a reception weight, the consistency of the transmission / reception weight is improved and the deterioration of transmission characteristics is reduced. It is an object to provide a multi-input multi-output propagation path signal transmission technique capable of
[0024]
[Means for Solving the Problems]
The invention of claim 1 is a multi-input multi-output propagation path signal transmission apparatus comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station is notified through a transmission signal generation unit, a transmission signal division unit that divides a transmission signal into a plurality of sequences, a transmission signal modulation unit that modulates each divided signal sequence, and a feedback line from the reception station A transmission weight generation unit that generates transmission weight information using the processed feedback information, and a transmission weight multiplication unit that multiplies the transmission weight information by the modulation signal of the transmission signal modulation unit,
The receiving station receives a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel state from the received signal, outputs communication channel information, and feedback that inputs communication channel information and generates feedback information An information generation unit, a feedback information processing unit that processes the feedback information according to a line condition of the feedback line, generates the processed feedback information, and feeds back to the transmitting station through the feedback line, and the processed feedback information A feedback information storage unit that holds a certain period of time and outputs the stored stored feedback information; a reception weight generation unit that generates reception weight information using the communication channel information and the stored feedback information; and a plurality of signal sequences To the received signal Comprising a reception weight multiplication unit for multiplying the serial reception weight information, the received signal demodulating unit for demodulating the received signal for each of the plurality of signal sequences, and,
The receiving station includes a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit.
[0025]
The invention of claim 2 is a receiving station having a plurality of antennas used for multi-input multi-output propagation path signal transmission, a plurality of antennas for receiving transmission signals from the transmitting station, and a communication channel from the received signals. A channel estimation unit that estimates the situation and outputs communication channel information, a feedback information generation unit that inputs communication channel information and generates feedback information, and processes the feedback information according to the line status of the feedback line A feedback information processing unit that generates feedback information and feeds back to the transmitting station through the feedback line; a feedback information storage unit that holds the processed feedback information for a certain period and outputs the stored stored feedback information; and the communication channel Information and the stored feedback information A reception weight generator for generating reception weight information; a reception weight multiplier for multiplying the reception signal by the reception weight information for each of a plurality of signal sequences; and a reception signal for demodulating the reception signal for each of the plurality of signal sequences A demodulation unit, and a reception signal combining unit that combines the output from the reception signal demodulation unit for each of the plurality of transmission signal sequences in correspondence with the transmission signal division method on the transmission station side. It is a feature.
[0026]
In the multi-input multi-output propagation path signal transmission apparatus according to the first aspect of the invention and the receiving station according to the second aspect of the invention, the transmitting station divides the transmission signal into a plurality of sequences and modulates each of the divided signal sequences. Then, this modulation signal is multiplied by transmission weight information generated using the processed feedback information notified through the feedback line from the receiving station side, and transmitted from the plurality of antennas to the propagation path.
[0027]
On the receiving station side, the transmission signal of the transmitting station is received by a plurality of antennas, the communication channel information is estimated from the received signal, feedback information is generated from this communication channel information, and the feedback information is further changed to the status of the feedback line. Processing feedback information is generated in accordance with the processing feedback, and this processing feedback information is fed back to the transmitting station through a feedback line. Further, the processing feedback information is held for a certain period, reception weight information is generated using the accumulated feedback information accumulated and the communication channel information, and the reception signal is multiplied by the reception weight information for each of a plurality of signal sequences. The received signal is demodulated for each transmission signal sequence. Then, the demodulated signals for each transmission signal sequence are combined corresponding to the transmission signal division unit on the transmission station side, and the original transmission signal is obtained and output.
[0028]
Thereby, in multi-input multi-output propagation path signal transmission, inconsistency between the transmission weight and the reception weight due to processing associated with feedback of the transmission weight is reduced, and deterioration of transmission characteristics is reduced.
[0029]
The invention of claim 3 is a multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station includes a transmission signal generation unit, a transmission signal division unit that divides the transmission signal into a plurality of signal sequences, a transmission signal modulation unit that modulates each of the divided transmission signal sequences, and the transmission signal modulation unit. A transmission weight multiplier for multiplying the modulated signal by quantized transmission weight information notified through a feedback line from the receiving station,
The receiving station, a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel condition from the received signal and outputs communication channel information, and a transmission that generates transmission weight information using the communication channel information A weight generation unit, a transmission weight quantization unit that performs quantization processing on the transmission weight information to generate the quantized transmission weight information, and feeds back to the transmitting station through the feedback line; and the quantized transmission weight information. A reception weight information is generated using a transmission weight storage unit that holds a certain period of time and outputs the accumulated quantization transmission weight, and the communication channel information and the quantization transmission weight information stored in the transmission weight storage unit A reception weight generator, and the reception signal is multiplied by the reception weight information for each of a plurality of signal sequences. That a reception weight multiplication unit, comprising a receiving signal demodulator for demodulating the received signal for each of the plurality of signal sequences, and,
The receiving station includes a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit.
[0030]
The invention of claim 4 is a receiving station having a plurality of antennas used for multi-input multi-output propagation path signal transmission, a plurality of antennas for receiving transmission signals from the transmitting station, and a communication channel from the received signals. A channel estimation unit that estimates the situation and outputs communication channel information; a transmission weight generation unit that generates transmission weight information using the communication channel information; and a quantized transmission weight information by performing a quantization process on the transmission weight information A transmission weight quantizing unit that generates and sends back to the transmitting station through a feedback line, a transmission weight transmission weight accumulating unit that holds the quantized transmission weight information for a certain period, and outputs the accumulated quantized transmission weight information; Using the communication channel information and the quantized transmission weight information stored in the transmission weight storage unit. A reception weight generation unit that generates data information, a reception weight multiplication unit that multiplies the reception signal by the reception weight information for each of a plurality of signal sequences, and a reception signal demodulation that demodulates the reception signal for each of the plurality of signal sequences And a reception signal combining unit that combines the outputs from the reception signal demodulation units for each of the plurality of transmission signal sequences to restore the original transmission signal. .
[0031]
In the multi-input multi-output propagation path signal transmission apparatus according to claim 3 and the receiving station according to claim 4, the transmitting station divides the transmission signal into a plurality of signal sequences, The modulated transmission signal is multiplied by the quantized transmission weight information that is modulated and notified through the feedback line from the receiving station side, and is transmitted to the propagation path through a plurality of antennas.
[0032]
On the receiving station side, transmission signals from the transmitting station are received by a plurality of antennas, communication channel information is estimated from the received signals, transmission weight information is generated using the communication channel information, and transmission weight information is quantized into transmission weight information. The quantized transmission weight information is generated by performing the quantization process, and is fed back to the transmitting station through the feedback line. At the same time, the quantization transmission weight information is retained for a certain period, reception weight information is generated using the communication channel information and the accumulated quantization transmission weight information, and the reception weight information is received in the reception signal for each of a plurality of signal sequences. And the received signal is demodulated for each of a plurality of transmission signal sequences. Then, the demodulated signals for each transmission signal sequence are combined corresponding to the transmission signal division unit on the transmission station side, and the original transmission signal is obtained and output.
[0033]
As a result, in multi-input multi-output propagation path signal transmission, inconsistency between the transmission weight and the reception weight due to delay accompanying transmission weight feedback is reduced, and deterioration of transmission characteristics is reduced.
[0034]
The invention of claim 5 is a multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station is notified through a transmission signal generation unit, a transmission signal division unit that divides a transmission signal into a plurality of sequences, a transmission signal modulation unit that modulates each divided signal sequence, and a feedback line from the reception station A transmission weight generation unit that generates transmission weight information using the quantized communication channel information that has been performed, and a transmission weight multiplication unit that multiplies the transmission weight information by the modulation signal of the transmission signal modulation unit,
The receiving station includes a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel state from the received signal and outputs communication channel information, and performs quantization processing on the communication channel information to perform the quantization A communication channel quantization unit that generates quantized communication channel information and feeds it back to the transmitting station through the feedback line; and a channel storage that holds the quantized communication channel information for a certain period and outputs the accumulated quantized communication channel information A transmission weight generation unit that generates transmission weight information using the quantized communication channel information stored in the channel storage unit, and the communication channel information and the transmission weight information output from the channel estimation unit. A reception weight generator for generating a reception weight, and the reception signal for each of a plurality of signal sequences. Comprising a reception weight multiplication unit that multiplies the weight information, the received signal demodulating unit for demodulating the received signal for each of the plurality of signal sequences, and,
The receiving station includes a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit.
[0035]
The invention of claim 6 is a receiving station having a plurality of antennas used for multi-input multi-output propagation path signal transmission, a plurality of antennas for receiving transmission signals from the transmitting station, and a communication channel from the received signals. A channel estimation unit that estimates the situation and outputs communication channel information; and a communication channel quantization unit that performs quantization processing on the communication channel information to generate quantized communication channel information and feeds back to the transmitting station through a feedback line A channel accumulator that holds the quantized communication channel information for a certain period and outputs the accumulated quantized communication channel information; and transmission weight information using the accumulated quantized communication channel information of the channel accumulator Using the transmission weight generation unit to be generated, the communication channel information output from the channel estimation unit, and the transmission weight information A reception weight generation unit that generates a reception weight; a reception weight multiplication unit that multiplies the reception signal by the reception weight information for each of a plurality of signal sequences; and a reception signal demodulation that demodulates the reception signal for each of the plurality of signal sequences And a reception signal combining unit that combines the outputs from the reception signal demodulation units for each of the plurality of transmission signal sequences to restore the original transmission signal. .
[0036]
In the multi-input multi-output propagation path signal transmission apparatus according to the fifth aspect of the invention and the receiving station according to the sixth aspect of the invention, the transmitting station divides the transmission signal into a plurality of sequences and modulates each of the divided signal sequences. Then, this modulated signal is multiplied by transmission weight information generated using the quantized communication channel information notified through the feedback line from the receiving station side, and transmitted to the propagation path through a plurality of antennas.
[0037]
On the receiving station side, transmission signals from the transmitting station are received by a plurality of antennas, communication channel information is estimated from the received signals, quantization processing is performed on the communication channel information to generate quantized communication channel information, Feedback is provided to the transmitting station through the feedback line. At the same time, the quantization communication channel information is held for a certain period, transmission weight information is generated using the accumulated quantization communication channel information, and reception weight is generated using the communication channel information and the transmission weight information. The reception signal is multiplied by the reception weight information for each of the plurality of signal sequences, and the reception signal is demodulated for each of the plurality of transmission signal sequences. Then, the demodulated signals for each transmission signal sequence are combined corresponding to the transmission signal division unit on the transmission station side, and the original transmission signal is obtained and output.
[0038]
As a result, in multi-input multi-output propagation path signal transmission, inconsistency between the transmission weight and the reception weight due to delay accompanying transmission weight feedback is reduced, and deterioration of transmission characteristics is reduced.
[0039]
The invention of claim 7 is a multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station includes a transmission signal generation unit, a transmission signal division unit that divides the transmission signal into a plurality of signal sequences, a transmission signal modulation unit that modulates each of the divided transmission signal sequences, and the transmission signal modulation unit. A transmission weight multiplier for multiplying the modulated signal by the corrected transmission weight information notified through the feedback line from the receiving station,
The receiving station, a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel condition from the received signal and outputs communication channel information, and a transmission that generates transmission weight information using the communication channel information A weight generation unit, a transmission weight storage unit that stores the transmission weight information output in the past by the transmission weight generation unit, past transmission weight information stored in the transmission weight storage unit, and feedback given in advance A transmission weight correction unit that corrects transmission weight information output from the transmission weight generation unit using the accompanying delay time information to generate the corrected transmission weight information and feeds back to the transmission station through the feedback line; and the transmission weight The corrected transmission weight information from the correction unit is held for a certain period and stored. A transmission weight storage unit that outputs the corrected transmission weight information, a reception weight generation unit that generates reception weight information using the communication channel information and the corrected transmission weight information stored in the transmission weight storage unit, and a plurality of A reception weight multiplier for multiplying the reception signal by the reception weight information for each signal sequence, and a reception signal demodulator for demodulating the reception signal for each of the plurality of signal sequences, and
The receiving station includes a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit.
[0040]
The invention of claim 8 is a receiving station having a plurality of antennas used for multi-input multi-output channel signal transmission, a plurality of antennas for receiving transmission signals from the transmitting station, and a communication channel from the received signals. A channel estimation unit that estimates the situation and outputs communication channel information, a transmission weight generation unit that generates transmission weight information using the communication channel information, and stores the transmission weight information output in the past by the transmission weight generation unit The transmission weight information output from the transmission weight generation unit using the transmission weight storage unit, the past transmission weight information stored in the transmission weight storage unit, and the delay time information associated with feedback provided in advance. To generate corrected transmission weight information and feed back to the transmitting station through a feedback line. The transmission weight storage unit that holds the correction transmission weight information from the normal part, the corrected transmission weight information from the transmission weight correction unit for a certain period, and outputs the stored corrected transmission weight information; the communication channel information and the transmission weight storage unit; A reception weight generation unit that generates reception weight information using the corrected transmission weight information, a reception weight multiplication unit that multiplies the reception weight information by the reception signal for each of a plurality of signal sequences, and each of the plurality of signal sequences. A reception signal demodulating unit that demodulates the received signal, and a reception signal combining unit that combines the outputs from the reception signal demodulation unit for each of the plurality of transmission signal sequences to restore the original transmission signal It is characterized by comprising.
[0041]
In the multi-input multi-output propagation path signal transmission device of the invention of claim 7 and the receiving station of the invention of claim 8, the transmission station divides the transmission signal into a plurality of signal sequences, The modulated transmission signal is multiplied by the corrected transmission weight information that is modulated and notified through the feedback line from the receiving station side, and is transmitted to the propagation path through a plurality of antennas.
[0042]
On the receiving station side, transmission signals from the transmitting station are received by a plurality of antennas, communication channel information is estimated from the received signals, and transmission weight information is generated using the communication channel information. Then, using the stored past transmission weight information and the delay time information associated with the feedback given in advance, the newly generated transmission weight information is corrected to generate corrected transmission weight information, and the transmitting station side Feedback through the feedback line. At the same time, the corrected transmission weight information is retained for a certain period, reception weight information is generated using the accumulated corrected transmission weight information and the communication channel information, and this reception weight information is added to the reception signal for each of a plurality of signal sequences. Multiplication is performed to demodulate the received signal for each of a plurality of transmission signal sequences. Then, the demodulated signals for each transmission signal sequence are combined corresponding to the transmission signal division unit on the transmission station side, and the original transmission signal is obtained and output.
[0043]
Thereby, in multi-input multi-output propagation path signal transmission, inconsistency between a transmission weight and a reception weight due to an error during transmission weight correction is reduced, and deterioration of transmission characteristics is reduced.
[0044]
The invention of claim 9 is a multi-input multi-output propagation path signal transmission apparatus comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station is notified through a transmission signal generation unit, a transmission signal division unit that divides a transmission signal into a plurality of sequences, a transmission signal modulation unit that modulates each divided signal sequence, and a feedback line from the reception station A transmission weight generation unit that generates transmission weight information using the corrected communication channel information, and a transmission weight multiplication unit that multiplies the modulation signal of the transmission signal modulation unit by the transmission weight information,
The receiving station includes a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel state from the received signal and outputs communication channel information, and the communication channel information that the channel estimation unit has output in the past A channel information storage unit for storing the communication channel information, and correcting the communication channel information by using past communication channel information stored in the channel information storage unit and delay time information associated with feedback provided in advance. A channel information correction unit that generates information and feeds back to the transmitting station through the feedback line; a channel storage unit that holds the corrected communication channel information for a certain period and outputs the stored corrected communication channel information; and the channel storage Input the corrected communication channel information stored in the A transmission weight generator for generating, a reception weight generator for generating a reception weight using the transmission weight information, a reception weight multiplier for multiplying the reception signal by the reception weight information for each of a plurality of signal sequences, A received signal demodulator that demodulates the received signal for each of a plurality of signal sequences, and
The receiving station includes a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit.
[0045]
The invention of claim 10 is a receiving station having a plurality of antennas used for multi-input multi-output propagation path signal transmission, a plurality of antennas for receiving transmission signals from the transmitting station, and a communication channel from the received signals. A channel estimation unit that estimates the situation and outputs communication channel information; a channel information storage unit that stores the communication channel information output in the past by the channel estimation unit; and a past communication stored in the channel information storage unit A channel information correction unit that corrects the communication channel information by using channel information and delay time information associated with feedback given in advance to generate corrected communication channel information, and feeds back to the transmitting station through a feedback line, and the correction Channel storage that retains communication channel information for a certain period and outputs the accumulated corrected communication channel information A transmission weight generation unit that receives the corrected communication channel information stored in the channel storage unit and generates transmission weight information, a reception weight generation unit that generates a reception weight using the transmission weight information, A reception weight multiplication unit that multiplies the reception signal by the reception weight information for each signal sequence, and a reception signal demodulation unit that demodulates the reception signal for each of the plurality of signal sequences, and the plurality of transmissions A reception signal combining unit that combines the outputs from the reception signal demodulation units for each signal sequence to restore the original transmission signal is provided.
[0046]
In the multi-input multi-output propagation path signal transmission apparatus according to the ninth aspect of the invention and the receiving station according to the tenth aspect of the invention, the transmitting station divides the transmission signal into a plurality of sequences and modulates each divided signal sequence Then, this modulated signal is multiplied by transmission weight information generated using the corrected communication channel information notified through the feedback line from the receiving station side, and transmitted to the propagation path through a plurality of antennas.
[0047]
On the receiving station side, transmission signals from the transmitting station are received by a plurality of antennas, communication channel information is estimated from the received signals, and given in advance with past communication channel information stored in the channel information storage unit The communication channel information newly obtained is corrected using the delay time information accompanying the feedback to generate corrected communication channel information, which is fed back to the transmitting station through the feedback line. Further, the corrected communication channel information is retained for a certain period, transmission weight information is calculated using the accumulated corrected communication channel information, reception weight is calculated using the transmission weight information, and a received signal is obtained for each of a plurality of signal sequences. Is multiplied by the reception weight information to demodulate the reception signal for each of a plurality of transmission signal sequences. Then, the demodulated signals for each transmission signal sequence are combined corresponding to the transmission signal division unit on the transmission station side, and the original transmission signal is obtained and output.
[0048]
As a result, in multi-input multi-output propagation path signal transmission, inconsistency between the transmission weight and the reception weight due to delay accompanying transmission weight feedback is reduced, and deterioration of transmission characteristics is reduced.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0050]
[First Embodiment] FIG. 1 shows a multi-input multi-output propagation path signal transmission apparatus according to a first embodiment of the present invention. The multi-input multi-output propagation path signal transmission apparatus of the present embodiment is roughly composed of three parts: a transmission station 100, a reception station 200, and a propagation path 300.
[0051]
The transmission station 100 includes a transmission signal generation unit 101 that generates transmission signals, # 1 to #K transmission signal division units 102, # 1 to #K transmission processing units 103, # 1 to #N addition units 104, and # 1. To #N transmission antennas 105 and a transmission weight generation unit 106. Each transmission processing unit 103 includes a transmission signal modulation unit 111, a multiplication unit 112, and a known symbol addition unit 1113.
[0052]
On the other hand, the receiving station 200 includes # 1 to #L receiving antennas 201, a known symbol separation unit 202, # 1 to #K equalization processing units 203, a channel estimation unit 204, a feedback information generation unit 205, and a feedback information processing unit 206. A feedback information storage unit 207, a reception weight generation unit 208, and a reception signal combining unit 209.
Each equalization processing unit 203 includes a multiplication unit 211 and a received signal demodulation unit 212.
[0053]
In the multi-input multi-output propagation path signal transmission apparatus according to the present embodiment, the transmitting station 100 receives feedback information from the receiving station 200 by using the feedback line 400, and the transmission weight generating unit 106 generates transmission weight information. The feedback information is a set of # 1 to #L as many as the number L of the receiving antennas 201, and each set of # 1 to #L includes the same number of weight information as the number N of the transmitting antennas 102. ing.
[0054]
The transmission weight generation unit 106 of the transmission station 100 generates transmission weight information generated based on the information fed back from the reception station 200. In general, eigenvalue calculation or singular value calculation is used to generate the transmission weight information. Specifically, when the channel matrix is A, the channel correlation matrix A ^H By performing eigenvalue decomposition of A, K (K = min (N, L)) eigenvectors e satisfying the following relationship: _k Get.
[0055]
[Equation 9]

Here, the symbol H indicates complex transposition. Also, λ _i Indicates an eigenvalue corresponding to the i-th eigenvector.
[0056]
Eigenvector e _k Is used to calculate the transmission weight vector for the kth stream.
[Expression 10]

Generate as follows.
[0057]
The transmission signal division unit 102 of the transmission station 100 refers to the transmission weight information and divides the transmission signal into the same number of sequences as the number of sets in which the transmission weight information is not all zero. Each of the divided transmission signal sequences is modulated by the transmission signal modulation unit 111, multiplied by a corresponding transmission weight, and a known symbol used for equalization processing on the receiving station 200 side is added. Each transmission signal sequence is added for each corresponding transmission antenna 105 by the adding unit 104 and transmitted from the transmission antenna 105 to the propagation path 300. Now, the k-th stream in the transmission signal sequence (stream) divided into K pieces is represented by S. _k (T), the number of transmission antennas is N, and the transmission weight vector (N rows × 1 column) corresponding to the k-th stream is W _Tk Then, the multiplexed transmission signal vector X (t) is
[Expression 11]

It becomes.
[0058]
The transmitted signal is distorted by the wireless propagation path 300 and then received by the receiving station 200. The state of distortion of the transmission signal sequence is determined by the shape of the propagation path 300 itself and the positional relationship between the transmission /

reception antennas

105 and 201. Now, it is assumed that the propagation path 300 is a uniform fading channel in which the influence of the delayed wave can be ignored in each channel.
[0059]
In receiving station 200, the received signal is separated into known symbols and transmission information symbols by known symbol division section 202. The transmission information symbols are input to the same number of equalization processing units 203 as each transmission signal sequence, and the known symbols are input to the channel estimation unit 204. The channel estimation unit 204 estimates the propagation path characteristics between each transmission and reception using the known symbols, and outputs communication channel information.
[0060]
This propagation path characteristic is shown by the following channel matrix A. However, L is the number of receiving antennas 201.
[0061]
[Expression 12]

The received signal r (t) received by each receiving antenna 201 has a noise vector n (t).
[Formula 13]

As shown.
[0062]
Feedback information generating section 205 generates feedback information using communication channel information output from channel estimating section 204. When transmission weight information is used as the feedback information, the feedback information generation unit 205 performs the same processing as the transmission weight generation unit 106 described above. Therefore, in this case, the transmission weight generation unit 106 is unnecessary on the transmission station 100 side. On the other hand, when the communication channel information is fed back as feedback information, the feedback information generation unit 205 is through.
[0063]
The generated feedback information is input to the feedback information processing unit 206 and the feedback information storage unit 207. The feedback information processing unit 206 processes the feedback information according to the bandwidth of the feedback line 400, the amount of feedback information, etc., and then outputs the processed feedback information. This processing feedback information is notified to the transmitting station 100 through the feedback line 400. The feedback information storage unit 207 holds the feedback information for a certain period until the processing feedback information is notified to the transmitting station 100 and the signal transmitted using the notification information is received by the receiving station 200. If the feedback information generation unit 205 is through, the same processing as the transmission weight generation unit 106 on the transmission station 100 side is performed after the end of the holding, and the transmission weight information is output as accumulated feedback information.
[0064]
After the predetermined period has elapsed, the feedback information accumulation unit 207 outputs the accumulated feedback information to the reception weight generation unit 208. Reception weight generation section 208 generates reception weight information using communication channel information and accumulated feedback information. At this time, the received weight vector (1 row × L column) W _Rk Is
[Expression 14]

Is generated as follows.
[0065]
The generated reception weight information is multiplied with the reception signal. Post-composition output y for the kth stream _k (T)
[Expression 15]

It becomes.
[0066]
By generating and using transmission / reception weights in this way, it is possible to extract only a desired stream without receiving any interference from other multiplexed streams. As a result, in the multi-input multi-output propagation path signal transmission apparatus according to the present embodiment, it is possible to dramatically increase the frequency utilization efficiency as compared with the case where only one conventional stream is transmitted.
[0067]
[Second Embodiment] Next, a multi-input multi-output propagation path signal transmission apparatus according to a second embodiment of the present invention will be described with reference to FIG.
[0068]
In the multi-input multi-output propagation path signal transmission apparatus of the first embodiment shown in FIG. 1, when reporting feedback information to a transmitting station using a feedback line, processing according to the bandwidth of the feedback line and the amount of feedback information Degradation due to may occur. As a result, consistency between transmission / reception weights may be disturbed, and transmission characteristics may deteriorate. In other words, transmission weight information before processing and transmission weight information after processing
[Expression 16]

Then, in the technique of the first embodiment, the reception weight is set to
[Expression 17]

Generate as
[0069]
The combined signal y at the receiving station 200 at this time _k (T)
[Expression 18]

It becomes. At this time,
[Equation 19]

Since there is an error associated with processing between the transmission weight information before processing and the transmission weight information after processing, the consistency between the transmission and reception weights may be disturbed. In this case, interference from other streams may occur. It is expected that the components cannot be sufficiently erased, and as a result, the transmission characteristics may be deteriorated.
[0070]
In the multi-input multi-output propagation path signal transmission apparatus of the present embodiment shown in FIG. 2, the same components as those of the multi-input multi-output propagation path signal transmission apparatus of the first embodiment shown in FIG. It attaches | subjects and shows the code | symbol. In the multi-input multi-output propagation path signal transmission apparatus according to the first embodiment, feedback information in a state where no processing is performed at the time of generating a reception weight in the reception station 200 is used, whereas in the present embodiment, The feature is that the processing feedback information processed by the feedback information processing unit 206 of the receiving station 200 is held in the feedback information storage unit 221 for a certain period of time and output to the reception weight generation unit 208 to generate the reception weight. To do.
[0071]
[Table 1]

Table 1 shows the relationship between the first embodiment and the second embodiment. In the first embodiment, eigenvalue calculation is performed based on the channel estimation value as shown in equation (10), and transmission / reception weights are calculated in a form consistent with the current propagation path and used during transmission. Is processed using the feedback line, the processing is performed according to the information speed of the feedback line, so the consistency with the received weight generated without being affected by the processing is disturbed, and the transmission capacity There could have been a situation where it deteriorated.
[0072]
On the other hand, in this embodiment, for the purpose of maintaining the consistency between the transmission weight and the reception weight, the reception weight is generated using the processed feedback information after the feedback information is processed. As a result, it is possible to reduce inconsistency between the transmission weight and the reception weight due to the processing associated with the transmission weight feedback. In other words, transmission weight information generated using feedback information before processing
[Expression 20]

The processing transmission weight information generated using the feedback information after processing
[Expression 21]

Then, in the method of the first embodiment, the reception weight is set to
[Expression 22]

Where it was generated as
[Expression 23]

Will be generated as The synthesized signal y at this time _k (T)
[Expression 24]

It becomes.
[0073]
With the above operation, in the multi-input multi-output propagation path signal transmission apparatus according to the second embodiment, it is possible to reduce the influence when an error due to processing at the time of feedback occurs, and to reduce the deterioration of transmission characteristics can do.
[0074]
[Third Embodiment] FIG. 3 shows a third embodiment of the present invention. The purpose of this embodiment is to reduce an error caused by quantization as an error caused by feedback. The technique of the first embodiment shown in FIG. 1 uses transmission weight information in a state where quantization is not performed when the reception weight is generated, whereas in this embodiment, transmission weight information is used as transmission weight information. The difference is that reception weight generation is performed using quantized transmission weight information after quantization in the quantization unit.
[0075]
As shown in FIG. 3, the multi-input multi-output propagation path signal transmission apparatus according to the present embodiment includes a transmission station 100 having a plurality of antennas 105, a reception station 200 having a plurality of antennas 201, and a radio propagation path 300. Composed.
[0076]
The transmitting station 100 has substantially the same configuration as that of the transmitting station according to the first embodiment of FIG. 1, but does not include a transmission weight generating unit and uses quantized transmission weight information fed back from the receiving station 200 side. Like to do.
[0077]
On the other hand, the receiving station 200 estimates communication channel conditions from signals received by the antennas 201 for each of a plurality of signal sequences, and generates transmission weight information using the channel estimation unit 204 that outputs communication channel information and the communication channel information. A transmission weight generation unit 231, a transmission weight quantization unit 232 that performs quantization processing on the transmission weight information to generate quantized transmission weight information and feeds it back to the transmission station 100 through the feedback line 400, and the quantized transmission weight information A reception weight information is generated using a transmission weight storage unit 233 that holds a certain period of time and outputs the accumulated quantization transmission weight, and communication channel information and the quantization transmission weight information stored in the transmission weight storage unit 233. Reception weight generator 234 and reception signal multiplied by reception weight information That a reception weight multiplication unit 211, and a reception signal demodulation unit 212 for demodulating the received signal. The receiving station 200 further combines the demodulated outputs from the reception signal demodulation units 212 of the equalization processing unit 203 for each of a plurality of transmission signal sequences in correspondence with the division method of the transmission signal division unit 102 on the transmission station 100 side. A reception signal combining unit 209 that outputs a reception signal is provided.
[0078]
In the first embodiment, the eigenvalue is calculated based on the channel estimation value as shown in the equation (10), and the transmission / reception weight is calculated in conformity with the current propagation path and used at the time of transmission. Because the transmission weight is quantized according to the information rate of the feedback line, the consistency with the received weight generated without being affected by the quantization is disturbed. It is expected that the transmission capacity will deteriorate.
[0079]
In order to cope with such a situation, this embodiment uses quantized transmission weight information after quantizing the transmission weight information in order to maintain consistency between the transmission weight and the reception weight. To generate a reception weight. As a result, inconsistency between the transmission weight and the reception weight due to the delay accompanying the transmission weight feedback can be reduced.
[0080]
In other words, transmission weight information before quantization and transmission weight information after quantization are
[Expression 25]

Then, in the first embodiment, the reception weight is
[Equation 26]

Where it was generated as
[Expression 27]

Will be generated as The synthesized signal y at this time _k (T)
[Expression 28]

It becomes.
[0081]
With the above operation, in the multi-input multi-output propagation path signal transmission according to the present embodiment, it is possible to reduce the influence when a quantization error due to feedback occurs, and to reduce the deterioration of transmission characteristics.
[0082]
[Fourth Embodiment] FIG. 4 shows a fourth embodiment of the present invention. In the third embodiment shown in FIG. 3, the transmission weight information calculated by the receiving station 200 is notified to the transmitting station 100 via the feedback line 400, whereas in this embodiment, the quantized communication channel information is changed. The transmission station 100 is notified using a feedback line 400, and transmission weight information is generated on the transmission station 100 side.
[0083]
The multi-input multi-output propagation path signal transmission apparatus according to the present embodiment includes a transmitting station 100 having a plurality of antennas 105, a receiving station 200 having a plurality of antennas 201, and a wireless propagation path 300. In addition, the same code | symbol is attached | subjected to the component which is common in 1st Embodiment shown in FIG.
[0084]
The transmission station 100 includes a transmission signal generation unit 101, a transmission signal division unit 102 that divides a transmission signal into a plurality of sequences, a transmission signal modulation unit 111 that modulates each divided signal sequence, and feedback from the reception station 200. A transmission weight generator 121 that generates transmission weight information using the quantized communication channel information notified through the line 400, a transmission weight multiplier 112 that multiplies the modulation signal of the transmission signal modulator 111 by transmission weight information, and a known A symbol adding unit 113 and an adding unit 104 are provided.
[0085]
On the other hand, the receiving station 200 estimates a communication channel state from signals received by the antennas 201 for each of a plurality of signal sequences, outputs a communication channel information, and performs a quantization process on the communication channel information to perform quantization. A communication channel quantization unit 241 that generates communication channel information and feeds it back to the transmitting station 100 through the feedback line 400, and a channel storage unit that holds the quantized communication channel information for a certain period and outputs the accumulated quantized communication channel information 242, transmission weight generation section 243 that generates transmission weight information using the quantized communication channel information stored in channel storage section 242, and communication channel information and transmission weight information output from channel estimation section 204. A reception weight generation unit 244 that generates reception weights, and a received signal A reception weight multiplication unit 211 multiplies the signal weight information, and a reception signal demodulation unit 212 for demodulating the received signal. The receiving station 200 further combines the demodulated signals output from the reception signal demodulation units 212 of the equalization processing units 203 for each of the plurality of transmission signal sequences in correspondence with the division method of the transmission signal division unit 102 on the transmission station 100 side. A reception signal combining unit 209 that outputs a reception signal is provided.
[0086]
In such a configuration, the transmission weight information is generated using communication channel information that has been quantized according to the information rate of the feedback line. However, in order to cope with such a situation, the present embodiment maintains the consistency between the transmission weight and the reception weight. For this purpose, a reception weight is generated using the quantized communication channel information after the communication channel information is quantized.
[0087]
Thereby, in the multi-input multi-output propagation path signal transmission system according to the present embodiment, it is possible to reduce inconsistency between the transmission weight and the reception weight due to the delay accompanying the feedback of the transmission weight. In other words, communication channel information before quantization and transmission weight information after quantization are
[Expression 29]

Then, the transmission weight is
[30]

Eigenvectors obtained by performing singular value decomposition or eigenvalue decomposition of
[31]

Can be expressed as follows.
[0088]
[Expression 32]

In contrast, in the first embodiment, the reception weight is increased.
[Expression 33]

According to the present embodiment,
[Expression 34]

Will be generated as The synthesized signal y at this time _k (T)
[Expression 35]

It becomes.
[0089]
With the above operation, in the multi-input multi-output propagation path signal transmission method according to the present embodiment, it is possible to reduce the influence when a quantization error due to feedback occurs, and to reduce the deterioration of transmission characteristics. .
[0090]
[Fifth Embodiment] FIG. 5 shows a fifth embodiment of the present invention. In the present embodiment, as an error caused by feedback, there is a problem of a correction error that occurs during weight correction performed for the purpose of compensation for feedback delay. In the first embodiment of FIG. 1, eigenvalue calculation is performed based on the channel estimation value as shown in equation (10), and transmission / reception weights are calculated in a form consistent with the current propagation path and used during transmission. Because the transmission weight information is transmitted using the feedback line, the transmission weight is received after a delay corresponding to the information speed of the feedback line. Therefore, the consistency between the transmission weight and the communication channel is disturbed, and the transmission capacity is reduced. Deterioration occurs.
[0091]
In order to cope with such a situation, a transmission weight correction unit can be used for the purpose of reducing the transmission weight associated with delay due to feedback and inconsistency between communication channels. In this case, for example, delay time information Based on the transmission weight information used in the past stored in the transmission weight storage unit, it is conceivable to correct the transmission weight by using primary extrapolation processing. The delay time information is calculated by, for example, measuring the time required for weight generation and correction at each of the transmitting station and the receiving station, and the time required until actual transmission is performed after the transmission weight information is received. Can do. However, it is considered that a mismatch occurs between the transmission / reception weight and the communication channel due to the accuracy of the delay time information and the error at the time of transmission weight correction.
[0092]
Therefore, the multi-input multi-output propagation path signal transmission apparatus of the present embodiment uses the corrected transmission weight information after correcting the transmission weight information for the purpose of maintaining the consistency between the transmission weight and the reception weight. The reception weight is generated.
[0093]
The configuration of the multi-input multi-output propagation path signal transmission apparatus according to this embodiment will be described with reference to FIG. The multi-input multi-output propagation path signal transmission apparatus according to the present embodiment includes a transmitting station 100 having a plurality of antennas 105, a receiving station 200 having a plurality of antennas 201, and a wireless propagation path 300. Since the transmitting station 100 has the same configuration as that of the third embodiment shown in FIG. 3, the same reference numerals are given to the common components, and the description thereof will be omitted.
[0094]
On the other hand, the receiving station 200 estimates communication channel conditions from signals received by the antennas 201 for each of a plurality of signal sequences, and generates transmission weight information using the channel estimation unit 204 that outputs communication channel information and the communication channel information. The transmission weight generation unit 231, the transmission weight storage unit 251 that stores transmission weight information output in the past by the transmission weight generation unit 231, and the past transmission weight information stored in the transmission weight storage unit 251 are given in advance. A transmission weight correction unit 252 that corrects transmission weight information output from the transmission weight generation unit 231 using delay time information 253 accompanying feedback to generate corrected transmission weight information, and feeds back to the transmission station 100 via the feedback line 400; Correction from transmission weight correction unit 252 The transmission weight storage unit 233 that holds the transmission weight information for a certain period and outputs the stored corrected transmission weight information, and the reception weight information using the communication channel information and the corrected transmission weight information stored in the transmission weight storage unit 233. A reception weight generation unit 234 for generating the reception signal, a reception weight multiplication unit 211 for multiplying the reception signal by the reception weight information, and a reception signal demodulation unit 212 for demodulating the reception signal. The receiving station 200 further combines the demodulated outputs from the reception signal demodulation units 212 of the equalization processing unit 203 for each of a plurality of transmission signal sequences in correspondence with the division method of the transmission signal division unit 102 on the transmission station 100 side. A reception signal combining unit 209 that outputs a reception signal is provided.
[0095]
With the above configuration, in the multi-input multi-output propagation path signal transmission apparatus according to the present embodiment, transmission weight information is corrected in receiving station 200 for the purpose of maintaining consistency between transmission weights and reception weights. A reception weight is generated using the later corrected transmission weight information. Thereby, in the multi-input multi-output channel signal transmission according to the present embodiment, it is possible to reduce inconsistency between the transmission weight and the reception weight due to an error at the time of transmission weight correction.
[0096]
In other words, transmission weight information before correction and transmission weight information after correction
[Expression 36]

Then, in the first embodiment, the reception weight is
[Expression 37]

In the present embodiment,
[Formula 38]

Will be generated as The synthesized signal y at this time _k (T)
[39]

Thus, it is possible to maintain consistency between transmission and reception weights in consideration of the influence of correction errors.
[0097]
As described above, in the multi-input multi-output propagation path signal transmission system according to the present embodiment, it is possible to reduce the influence when an error due to feedback occurs, and it is possible to reduce deterioration of transmission characteristics.
[0098]
[Sixth Embodiment] FIG. 6 shows a sixth embodiment of the present invention. In the transmission system according to the fifth embodiment, the transmission weight information calculated by the receiving station is notified to the transmitting station via the feedback line, whereas in this embodiment, the corrected communication channel information is sent to the transmitting station via the feedback line. And transmitting weight information is generated on the transmitting station side.
[0099]
The configuration of this embodiment will be described with reference to FIG. The multi-input multi-output propagation path signal transmission apparatus according to the present embodiment includes a transmitting station 100 having a plurality of antennas 105, a receiving station 200 having a plurality of antennas 201, and a wireless propagation path 300.
[0100]
The transmission station 100 is almost the same as the embodiment shown in FIGS. 2 and 4, but the transmission weight generation unit 131 generates transmission weight information using the corrected communication channel information fed back from the reception station 200. Is different from the others.
[0101]
The receiving station 200 also includes a plurality of antennas 201 that receive transmission signals for each of a plurality of signal sequences, a channel estimation unit 204 that estimates communication channel conditions from the received signals and outputs communication channel information, and a channel estimation unit 204. Channel information storage unit 261 for storing communication channel information output in the past, communication channel information using past communication channel information stored in channel information storage unit 261 and delay time information 253 accompanying feedback given in advance A channel information correction unit 262 that corrects information to generate corrected communication channel information, feeds it back to the transmitting station 100 through the feedback line 400, holds the corrected communication channel information for a certain period, and outputs the accumulated corrected communication channel information. Channel storage unit 242 and storage of channel storage unit 242 The received corrected communication channel information is input, a transmission weight generation unit 243 that generates transmission weight information, a reception weight generation unit 244 that generates a reception weight using the transmission weight information, and a reception signal is multiplied by the reception weight information A reception weight multiplication unit 211 and a reception signal demodulation unit 212 that demodulates the reception signal are provided. The receiving station 200 also combines the demodulated output from each of the reception signal demodulation units 212 of the equalization processing unit 203 for each of a plurality of transmission signal sequences in correspondence with the division method of the transmission signal division unit 102 on the transmission station 100 side, A reception signal combining unit 209 that outputs a reception signal is provided.
[0102]
When the transmission weight information is generated using the communication channel information affected by the delay according to the information rate of the feedback line 400, the consistency with the generated reception weight without being affected by the delay is disturbed, and the transmission capacity Can happen.
[0103]
In order to cope with such a situation, the present embodiment uses corrected communication channel information after correction processing is performed on communication channel information in order to maintain consistency between transmission weights and reception weights. To generate a reception weight. Thereby, in this Embodiment, inconsistency of the transmission weight by the delay accompanying the feedback of transmission weight and a reception weight can be reduced.
[0104]
In other words, communication channel information before correction and communication channel information after correction
[Formula 40]

Then, the transmission weight is
[Expression 41]

Eigenvectors obtained by performing singular value decomposition or eigenvalue decomposition of
[Expression 42]

Can be expressed as follows.
[0105]
[Expression 43]

On the other hand, in the first embodiment, the reception weight is set to
(44)

Was generated as. The synthesized signal y at this time _k (T)
[Equation 45]

It becomes.
[0106]
On the other hand, in this embodiment,
[Equation 46]

Will be generated as The synthesized signal y at this time _k (T)
[Equation 47]

It becomes. The transmission weight is
[Formula 48]

(24) is less affected by inconsistency.
[0107]
By the above operation, in the multi-input multi-output propagation path signal transmission according to the present embodiment, it is possible to reduce the influence when a delay due to feedback occurs, and it is possible to reduce the deterioration of transmission characteristics.
[0108]
【Example】
A computer simulation was performed for the purpose of evaluating the improvement effect in the configuration shown in the third embodiment of the present invention. The simulation conditions are shown below.
[0109]
The number of transmission /

reception antennas

105 and 201 is both four, and the modulation scheme is configured to adaptively switch between BPSK, QPSK, 16QAM, and 64QAM according to the channel quality. Channel coding is not performed. Each transmission signal sequence is transmitted with equal power. The propagation path 300 assumed one-wave Rayleigh fading between the transmitting and receiving antennas, and the correlation characteristics between the transmission branches and the reception branches were set with reference to Case II of the following reference. The average signal power to noise power ratio was 20 dB.
[0110]
FIG. 7 shows the results of evaluating the transmission methods according to the first and third embodiments of the present invention with the horizontal axis representing the total number of quantization bits used per frame and the vertical axis representing the average throughput. . In both systems, the throughput decreases as the value on the horizontal axis decreases, but the transmission system according to the third embodiment can maintain better characteristics than the transmission system according to the first embodiment. Was confirmed.
[0111]
[References]
“Joint 3GPP 3GPP2 Spatial Channel Modeling AHG Status Report”, RAN1 # 27, July 2-5, 2002.
[0112]
【The invention's effect】
As described above, according to the present invention, since weights can be set in consideration of consistency of transmission / reception weights, deterioration of characteristics due to quantization accompanying feedback can be reduced, and as a result, good transmission characteristics can be obtained. Can be maintained.
[Brief description of the drawings]
FIG. 1 is a block diagram of a multi-input multi-output propagation path signal transmission apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram of a multi-input multi-output propagation path signal transmission apparatus according to a second embodiment of the present invention.
FIG. 3 is a block diagram of a multi-input multi-output propagation path signal transmission apparatus according to a third embodiment of the present invention.
FIG. 4 is a block diagram of a multi-input multi-output propagation path signal transmission apparatus according to a fourth embodiment of the present invention.
FIG. 5 is a block diagram of a multi-input multi-output propagation path signal transmission apparatus according to a fifth embodiment of the present invention.
FIG. 6 is a block diagram of a multi-input multi-output propagation path signal transmission apparatus according to a sixth embodiment of the present invention.
FIG. 7 is a graph comparing transmission characteristics of the transmission scheme according to the first embodiment of the present invention and the transmission scheme according to the third embodiment.
FIG. 8 is a block diagram of a conventional multi-input multi-output propagation path signal transmission apparatus.
[Explanation of symbols]
100 transmitting station
101 Transmission signal generator
102 Transmission signal division unit
103 Signal processor
104 Adder
105 Antenna
106 Transmission weight generator
111 Transmission signal modulator
112 Transmission weight multiplier
113 Known symbol adding unit
121 Transmission weight generator
131 Transmission weight generator
200 Receiving station
201 Antenna
202 Known symbol separator
203 Equalizer
204 Channel estimation unit
205 Feedback information generator
206 Feedback information processing section
208 Receive weight generator
209 Received signal coupling unit
211 Receive weight multiplier
212 Received signal demodulator
221 Feedback information storage unit
231 Transmission weight generator
232 Transmission weight quantization section
233 Transmission weight storage unit
234 Receive Weight Generation Unit
241 Communication channel quantization unit
242 Channel storage unit
243 Transmission weight generator
244 Receive Weight Generation Unit
251 Transmission weight storage unit
252 Transmission weight correction unit
253 Delay time information
261 channel information storage unit
262 Channel information correction unit
300 propagation path
400 Feedback line

Claims

A multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station is notified through a transmission signal generation unit, a transmission signal division unit that divides a transmission signal into a plurality of sequences, a transmission signal modulation unit that modulates each divided signal sequence, and a feedback line from the reception station A transmission weight generation unit that generates transmission weight information using the processed feedback information, and a transmission weight multiplication unit that multiplies the transmission weight information by the modulation signal of the transmission signal modulation unit,
The receiving station receives a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel state from the received signal, outputs communication channel information, and feedback that inputs communication channel information and generates feedback information An information generation unit, a feedback information processing unit that processes the feedback information according to a line condition of the feedback line, generates the processed feedback information, and feeds back to the transmitting station through the feedback line, and the processed feedback information A feedback information storage unit that holds a certain period of time and outputs the stored stored feedback information; a reception weight generation unit that generates reception weight information using the communication channel information and the stored feedback information; and a plurality of signal sequences To the received signal Comprising a reception weight multiplication unit for multiplying the serial reception weight information, the received signal demodulating unit for demodulating the received signal for each of the plurality of signal sequences, and,
The multi-input multi-output propagation characterized in that the receiving station comprises a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit Road signal transmission device.

A receiving station with a plurality of antennas used for multi-input multi-output propagation path signal transmission,
A plurality of antennas that receive transmission signals from a transmitting station, a channel estimation unit that estimates communication channel conditions from received signals and outputs communication channel information, and feedback information generation that inputs communication channel information and generates feedback information A feedback information processing unit that processes the feedback information according to a line condition of the feedback line to generate processed feedback information, and feeds back to the transmitting station through the feedback line, and holds the processed feedback information for a certain period. A feedback information storage unit that outputs the stored stored feedback information, a reception weight generation unit that generates reception weight information using the communication channel information and the stored feedback information, and the received signal for each of a plurality of signal sequences To the receiving way Comprising a reception weight multiplication unit for multiplying the information, the received signal demodulating unit for demodulating the received signal for each of the plurality of signal sequences, and,
A receiving station, comprising: a reception signal combining unit that combines the outputs from the reception signal demodulation units for each of the plurality of transmission signal sequences to restore the original transmission signal.

A multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station includes a transmission signal generation unit, a transmission signal division unit that divides the transmission signal into a plurality of signal sequences, a transmission signal modulation unit that modulates each of the divided transmission signal sequences, and the transmission signal modulation unit. A transmission weight multiplier for multiplying the modulated signal by quantized transmission weight information notified through a feedback line from the receiving station,
The receiving station, a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel condition from the received signal and outputs communication channel information, and a transmission that generates transmission weight information using the communication channel information A weight generation unit, a transmission weight quantization unit that performs quantization processing on the transmission weight information to generate the quantized transmission weight information, and feeds back to the transmitting station through the feedback line; and the quantized transmission weight information. A reception weight information is generated using a transmission weight storage unit that holds a certain period of time and outputs the accumulated quantization transmission weight, and the communication channel information and the quantization transmission weight information stored in the transmission weight storage unit A reception weight generator, and the reception signal is multiplied by the reception weight information for each of a plurality of signal sequences. That a reception weight multiplication unit, comprising a receiving signal demodulator for demodulating the received signal for each of the plurality of signal sequences, and,
The multi-input multi-output propagation characterized in that the receiving station comprises a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit Road signal transmission device.

A receiving station with a plurality of antennas used for multi-input multi-output propagation path signal transmission,
A plurality of antennas for receiving transmission signals from a transmitting station, a channel estimation unit for estimating communication channel conditions from the received signals and outputting communication channel information, and transmission weight generation for generating transmission weight information using the communication channel information A transmission weight quantization unit that performs quantization processing on the transmission weight information to generate quantized transmission weight information and feeds it back to the transmitting station through a feedback line, and holds the quantized transmission weight information for a certain period. A transmission weight transmission weight storage unit that outputs the accumulated quantized transmission weight information, and reception weight information that is generated using the communication channel information and the quantized transmission weight information stored in the transmission weight storage unit. A weight generator, and multiplying the received signal by the received weight information for each of a plurality of signal sequences A reception weight multiplication unit which, provided with a receiving signal demodulator for demodulating the received signal for each of the plurality of signal sequences, and,
A receiving station, comprising: a reception signal combining unit that combines the outputs from the reception signal demodulation units for each of the plurality of transmission signal sequences to restore the original transmission signal.

A multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station is notified through a transmission signal generation unit, a transmission signal division unit that divides a transmission signal into a plurality of sequences, a transmission signal modulation unit that modulates each divided signal sequence, and a feedback line from the reception station A transmission weight generation unit that generates transmission weight information using the quantized communication channel information that has been performed, and a transmission weight multiplication unit that multiplies the transmission weight information by the modulation signal of the transmission signal modulation unit,
The receiving station includes a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel state from the received signal and outputs communication channel information, and performs quantization processing on the communication channel information to perform the quantization A communication channel quantization unit that generates quantized communication channel information and feeds it back to the transmitting station through the feedback line; and a channel storage that holds the quantized communication channel information for a certain period and outputs the accumulated quantized communication channel information A transmission weight generation unit that generates transmission weight information using the quantized communication channel information stored in the channel storage unit, and the communication channel information and the transmission weight information output from the channel estimation unit. A reception weight generator for generating a reception weight, and the reception signal for each of a plurality of signal sequences. Comprising a reception weight multiplication unit that multiplies the weight information, the received signal demodulating unit for demodulating the received signal for each of the plurality of signal sequences, and,
The multi-input multi-output propagation characterized in that the receiving station comprises a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit Road signal transmission device.

A receiving station with a plurality of antennas used for multi-input multi-output propagation path signal transmission,
A plurality of antennas for receiving transmission signals from a transmitting station, a channel estimation unit for estimating communication channel conditions from the received signals and outputting communication channel information, and a quantization communication channel by performing quantization processing on the communication channel information A communication channel quantization unit that generates information and feeds back to the transmitting station through a feedback line; a channel storage unit that holds the quantized communication channel information for a certain period and outputs the accumulated quantized communication channel information; and A transmission weight generation unit that generates transmission weight information using the quantized communication channel information stored in the channel storage unit, and a reception weight that is generated using the communication channel information output from the channel estimation unit and the transmission weight information A reception weight generation unit, and the reception weight information in the reception signal for each of a plurality of signal sequences Comprising a reception weight multiplication unit for multiplying the received signal demodulating unit for demodulating the received signal for each of the plurality of signal sequences, and,
A receiving station, comprising: a reception signal combining unit that combines the outputs from the reception signal demodulation units for each of the plurality of transmission signal sequences to restore the original transmission signal.

A multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station includes a transmission signal generation unit, a transmission signal division unit that divides the transmission signal into a plurality of signal sequences, a transmission signal modulation unit that modulates each of the divided transmission signal sequences, and the transmission signal modulation unit. A transmission weight multiplier for multiplying the modulated signal by the corrected transmission weight information notified through the feedback line from the receiving station,
The receiving station, a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel condition from the received signal and outputs communication channel information, and a transmission that generates transmission weight information using the communication channel information A weight generation unit, a transmission weight storage unit that stores the transmission weight information output in the past by the transmission weight generation unit, past transmission weight information stored in the transmission weight storage unit, and feedback given in advance A transmission weight correction unit that corrects transmission weight information output from the transmission weight generation unit using the accompanying delay time information to generate the corrected transmission weight information and feeds back to the transmission station through the feedback line; and the transmission weight The corrected transmission weight information from the correction unit is held for a certain period and stored. A transmission weight storage unit that outputs the corrected transmission weight information, a reception weight generation unit that generates reception weight information using the communication channel information and the corrected transmission weight information stored in the transmission weight storage unit, and a plurality of A reception weight multiplier for multiplying the reception signal by the reception weight information for each signal sequence, and a reception signal demodulator for demodulating the reception signal for each of the plurality of signal sequences, and
The multi-input multi-output propagation characterized in that the receiving station comprises a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit Road signal transmission device.

A receiving station with a plurality of antennas used for multi-input multi-output propagation path signal transmission,
A plurality of antennas for receiving transmission signals from a transmitting station, a channel estimation unit for estimating communication channel conditions from the received signals and outputting communication channel information, and transmission weight generation for generating transmission weight information using the communication channel information A transmission weight storage unit that stores the transmission weight information output in the past by the transmission weight generation unit, past transmission weight information stored in the transmission weight storage unit, and a delay associated with feedback given in advance A transmission weight correction unit that corrects transmission weight information output from the transmission weight generation unit using time information to generate corrected transmission weight information and feeds back to the transmission station through a feedback line; and a transmission weight correction unit from the transmission weight correction unit The corrected transmission weight information is retained for a certain period, and the stored corrected transmission weight is stored. A transmission weight accumulation unit that outputs data weight information, a reception weight generation unit that generates reception weight information using the communication channel information and the corrected transmission weight information accumulated in the transmission weight accumulation unit, and a plurality of signal sequences A reception weight multiplication unit that multiplies the reception signal by the reception weight information, and a reception signal demodulation unit that demodulates the reception signal for each of the plurality of signal sequences, and
A receiving station, comprising: a reception signal combining unit that combines the outputs from the reception signal demodulation units for each of the plurality of transmission signal sequences to restore the original transmission signal.

A multi-input multi-output propagation path signal transmission device comprising a transmitting station having a plurality of antennas and a receiving station having a plurality of antennas,
The transmission station is notified through a transmission signal generation unit, a transmission signal division unit that divides a transmission signal into a plurality of sequences, a transmission signal modulation unit that modulates each divided signal sequence, and a feedback line from the reception station A transmission weight generation unit that generates transmission weight information using the corrected communication channel information, and a transmission weight multiplication unit that multiplies the modulation signal of the transmission signal modulation unit by the transmission weight information,
The receiving station includes a plurality of antennas that receive the transmission signal, a channel estimation unit that estimates a communication channel state from the received signal and outputs communication channel information, and the communication channel information that the channel estimation unit has output in the past A channel information storage unit for storing the communication channel information, and correcting the communication channel information by using past communication channel information stored in the channel information storage unit and delay time information associated with feedback provided in advance. A channel information correction unit that generates information and feeds back to the transmitting station through the feedback line; a channel storage unit that holds the corrected communication channel information for a certain period and outputs the stored corrected communication channel information; and the channel storage Input the corrected communication channel information stored in the A transmission weight generator for generating, a reception weight generator for generating a reception weight using the transmission weight information, a reception weight multiplier for multiplying the reception signal by the reception weight information for each of a plurality of signal sequences, A received signal demodulator that demodulates the received signal for each of a plurality of signal sequences, and
The multi-input multi-output propagation characterized in that the receiving station comprises a reception signal combining unit that combines outputs from the reception signal demodulating unit for each of the plurality of transmission signal sequences corresponding to the transmission signal dividing unit Road signal transmission device.

A receiving station with a plurality of antennas used for multi-input multi-output propagation path signal transmission,
A plurality of antennas that receive transmission signals from a transmission station, a channel estimation unit that estimates communication channel conditions from received signals and outputs communication channel information, and stores the communication channel information output by the channel estimation unit in the past Channel information storage unit, and past communication channel information stored in the channel information storage unit and delay time information associated with feedback provided in advance to correct the communication channel information and generate corrected communication channel information A channel information correction unit that feeds back to the transmitting station through a feedback line, a channel storage unit that holds the corrected communication channel information for a certain period, and outputs the stored corrected communication channel information, and is stored in the channel storage unit. Transmission to generate transmission weight information A weight generation unit; a reception weight generation unit that generates a reception weight using the transmission weight information; a reception weight multiplication unit that multiplies the reception weight information by the reception signal for each of a plurality of signal sequences; and the plurality of signals A received signal demodulator for demodulating the received signal for each series, and
A receiving station, comprising: a reception signal combining unit that combines the outputs from the reception signal demodulation units for each of the plurality of transmission signal sequences to restore the original transmission signal.