JP2004364120A

JP2004364120A - Radio base station system

Info

Publication number: JP2004364120A
Application number: JP2003162277A
Authority: JP
Inventors: Hiroaki Oba; 弘明大庭
Original assignee: NEC Saitama Ltd
Current assignee: NEC Saitama Ltd
Priority date: 2003-06-06
Filing date: 2003-06-06
Publication date: 2004-12-24
Anticipated expiration: 2023-06-06
Also published as: JP3872039B2

Abstract

<P>PROBLEM TO BE SOLVED: To measure a delay time between a radio base station device and a remote radio transmitting/receiving part transmitting/receiving antenna with high accuracy without stopping the existing service. <P>SOLUTION: The radio base station device 1 is subjected to communication connection to a remote radio transmitting/receiving part 101. A radio transmitting/receiving part 102 is subjected to communication connection to the radio transmitting/receiving part 101. A radio transmitting/receiving part 10N is subjected to communication connection to the radio transmitting/receiving part 102, and subsequent radio transmitting/receiving parts are cascaded in a similar manner. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は無線基地局システムに関し、特に無線基地局装置と遠方の無線送受信部間との伝送信号をＣＤＭＡ方式により多重化し、既存のサービスを停止することなく無線基地局装置と遠方の無線送受信部との遅延時間を高精度に測定できる無線基地局システムに関する。
【０００２】
【従来の技術】
一般に、送受信アンテナが複数個遠方にある無線基地局システムにおいては、時分割多重化方式で各送受信アンテナの信号を多重している。
【０００３】
図９は従来の時分割方式での伝送フォーマットを示す図である。
【０００４】
このような時分割方式で遅延時間を測定しようとした場合、例えば８本のアンテナ１用〜アンテナ８用の送受信アンテナをサポートするシステムでは、図９に示すように各送受信アンテナに割り当てられる時間は全体の時間の１／８であるため、１／８の単位でしか遅延量の測定精度はない。
【０００５】
また、この例の場合は送受信アンテナ１用〜アンテナ８用のすべてのデータを遅延量測定のための制御信号に割り当てた場合で、運用中に遅延量を再度測定したい場合はベースバンド信号を停止する必要があるため、一旦運用中のサービスを停止する必要がある。
【０００６】
遅延時間の調整では、遅延時間測定器を用いて遅延時間を測定し、この測定結果をもとに遅延時間可変要求が調整されている。
【０００７】
本発明の目的は、送受信アンテナが複数個遠方にある無線基地局システムにおいて、無線基地局装置と遠方の無線送受信部送受信アンテナ間との伝送信号をデジタル信号とし、送信側で複数の送受信アンテナのデジタル信号をＣＤＭＡ（ＣｏｄｅＤｉｖｉｓｉｏｎＭｕｌｔｉｐｌｅＡｃｃｅｓｓ）方式により多重し、受信側で複数の送受信アンテナのデジタル信号を分離することにより既存のサービスを停止することなく、無線基地局装置と遠方の無線送受信部送受信アンテナ間との遅延時間を高精度に測定できる無線基地局システムを供給できることにある。
【０００８】
従来の無線基地局システムは、基地局の可変指向性アンテナ各素子の信号を時分割多重装置で時分割多重し、この時分割多重された信号を同一の光ファイバ内を伝送させることでアンテナ各素子間の相対位置変化をなくし、アンテナ各素子間の相対位相差を維持している（例えば、特許文献１参照。）。
【０００９】
また、集中基地局に送受信装置を設置し、無線基地局に送受信アンテナを設置して無線基地局と集中基地局との間を伝送路で接続し、送受信装置と送受信アンテナ間の信号を伝送するための全二重基地局間伝送路を含む基地局装置及び伝送路の状態を監視しているものもある（例えば、特許文献２参照。）。
【００１０】
【特許文献１】
特開２００１−９４３３２号公報（第３−５頁、図１、図２）
【特許文献２】
特開平５−３２７６３２号公報（第２−３頁、図１）
【００１１】
【発明が解決しようとする課題】
上述した従来の無線基地局システムは、このような時分割方式で遅延時間を測定しようとした場合、各送受信アンテナに割り当てられる時間は全体の時間の１／８であるため、１／８の単位でしか遅延量の測定精度がないという欠点を有している。
【００１２】
また、送受信アンテナ１用〜アンテナ８用のすべてのデータを遅延量測定のための制御信号に割り当てた場合、運用中に遅延量を再度測定したい場合はベースバンド信号を停止する必要があるため、一旦運用中のサービスを停止する必要があるという欠点を有している。
【００１３】
本発明の目的は、送受信アンテナを有す無線送受信部が複数個遠方にある無線基地局システムにおいて、無線基地局装置と無線送受信部の送受信アンテナ間の伝送信号をデジタル信号とし、送信側で複数の送受信アンテナのデジタル信号をＣＤＭＡ方式により多重し、受信側で複数の送受信アンテナのデジタル信号を分離することにより既存のサービスを停止することなく、無線基地局装置と遠方の無線送受信部送受信アンテナ間との遅延時間を高精度に測定できる無線基地局システムを提供することにある。
【００１４】
【課題を解決するための手段】
本発明の第１の無線基地局システムは、無線基地局装置及び送受信アンテナが複数個遠方にある無線基地局システムであって、
前記無線基地局装置と前記送受信アンテナ間の伝送信号をデジタル信号とし、送信側で複数の前記送受信アンテナのデジタル信号をＣＤＭＡ（ＣｏｄｅＤｉｖｉｓｉｏｎＭｕｌｔｉｐｌｅＡｃｃｅｓｓ）方式により多重し、受信側で複数の前記送受信アンテナのデジタル信号を分離することにより、前記無線基地局装置と前記送受信アンテナ間の遅延時間を測定することを特徴としている。
【００１５】
本発明の第２の無線基地局システムは、
無線基地局装置と、この無線基地局装置と通信接続する遠方のカスケード接続された複数の無線送受信部とを備え、
前記無線基地局装置は、
遠方の前記複数の無線送受信部へ各々複数の第１の送信合成信号を出力し、かつ遠方の前記複数の無線送受信部からの各々の複数の受信合成信号を入力し、各々がデータ処理を行う複数のデータ処理部と；
前記複数のデータ処理部からの前記複数の第１の送信合成信号を入力し拡散処理を行い、複数の第２の送信合成信号を出力する拡散部と；
この拡散部から出力される前記複数の第２の送信合成信号を入力し、これらを多重して送信多重信号を出力する多重部と；
この多重部から出力された前記送信多重信号の電気信号を光信号に変換して、前記無線送受信部に送信多重化信号として出力する電気／光変換部と；
前記無線送受信部からの受信多重化信号を入力して、この光信号を電気信号に変換し受信多重信号として出力する光／電気変換部と；
この光／電気変換部から出力された前記受信多重信号を入力して逆拡散し、前記複数の受信合成信号に分離出力する逆拡散部と；
前記拡散部からの前記複数の第２の送信合成信号の拡散タイミング信号及び前記逆拡散部からの前記複数の受信合成信号の逆拡散タイミング信号を入力し、送受信信号の遅延時間を測定する遅延測定部と；
を備えたことを特徴としている。
【００１６】
本発明の第３の無線基地局システムは、
無線基地局装置と、この無線基地局装置と通信接続する遠方のカスケード接続された複数の無線送受信部とを備え、
前記無線送受信部は、
前記無線基地局装置から出力された送信多重化信号を入力し、光信号を電気信号に変換する第１の光／電気変換部と；
この第１の光／電気変換部が出力する前記送信多重信号を入力し、この送信多重信号を２分配して、第１の送信多重信号及び第２の送信多重信号を出力する分離部と；
この分離部が出力した前記第１の送信多重信号の電気信号を光信号に変換し、前記無線送受信部に出力する第１の電気／光変換部と；
前記分離部が出力した前記第２の送信多重信号を入力し、逆拡散により必要な送信合成信号を抽出して出力し、かつ逆拡散タイミング信号を出力する逆拡散部と；
この逆拡散部が出力した前記送信合成信号を入力して、送信ベ−スバンド信号と制御信号を分離し、送信ベースバンド信号をデジタル・アナログ変換及び周波数変換し、送信無線信号として出力する送信無線処理部と；
この送信無線処理部から出力された前記送信無線信号を入力し出力するサーキュレータ部と；
このサーキュレータ部から出力された無線信号を外部へ送信し、かつ外部からの無線信号を受信するアンテナ部と；
このアンテナ部及び前記サーキュレータ部からの受信無線信号を周波数変換及びアナログ・デジタル変換した受信ベースバンド信号を生成し、この受信ベースバンド信号と制御信号を合成することで、第１の受信合成信号を出力する受信無線処理部と；
この受信無線処理部が出力した第１の受信合成信号と前記逆拡散部から出力された前記逆拡散タイミング信号を入力し拡散処理を行い、第２の受信合成信号を出力する拡散部と；
前記無線送受信部からの光信号を電気信号に変換し、第１の受信多重化信号として出力する第２の光／電気変換部と；
前記拡散部が出力した前記第２の受信合成信号及び前記第２の光／電気変換部が出力した前記第１の受信多重化信号を多重化し、第２の受信多重化信号として出力する多重部と；
この多重部が出力した前記第２の受信多重化信号の電気信号を光信号に変換し前記無線基地局装置に出力する第２の電気／光変換部と；
を備えたことを特徴としている。
【００１７】
本発明の第４の無線基地局システムは、前記第２または第３の無線基地局システムにおいて、
前記無線基地局装置と前記無線送受信部間並びに前記無線送受信部と他の無線送受信部との間は、長距離伝送に適した光ファイバを使用して光シリアル伝送させることを特徴としている。
【００１８】
本発明の第５の無線基地局システムは、前記第４の無線基地局システムにおいて、
前記無線基地局装置は、送受信各一本の光ファイバで８つの前記無線送受信部が接続されていることを特徴としている。
【００１９】
本発明の第６の無線基地局システムは、前記第２の無線基地局システムにおいて、
前記無線基地局装置が有する前記複数のデータ処理部の各々は、前記無線送受信部に出力される送信ベースバンド信号と送信制御信号を時分割多重した前記複数の第１の送信合成信号を、前記拡散部に出力することを特徴としている。
【００２０】
本発明の第７の無線基地局システムは、前記第２の無線基地局システムにおいて、
前記無線基地局装置が有する前記多重部に入力された８本の前記第２の送信合成信号は、ＣＤＭＡ（ＣｏｄｅＤｉｖｉｓｉｏｎＭｕｌｔｉｐｌｅＡｃｃｅｓｓ）方式を用いコード多重させることにより、伝送レートを変えずに多重し、前記送信多重信号として前記電気／光変換部に出力されることを特徴としている。
【００２１】
本発明の第８の無線基地局システムは、前記第２または第７の無線基地局システムにおいて、
前記無線基地局装置が有する前記電気／光変換部に入力される前記送信多重信号は、パラレルデータをシリアルデータに変換した後、電気から光信号に変換され、光信号に変換された前記送信多重化信号は、光ファイバを経由して前記無線送受信部に出力されることを特徴としている。
【００２２】
本発明の第９の無線基地局システムは、前記第２の無線基地局システムにおいて、
前記無線基地局装置が有する遅延測定部は、
前記拡散部からの前記拡散タイミング信号及び前記逆拡散部からの前記逆拡散タイミング信号を入力し、前記複数の無線送受信部の各々に送信した拡散コードの先頭と、前記複数の無線送受信部の各々から受信した前記拡散コードの先頭との差から送受信光ファイバ遅延を算出し、前記無線基地局装置と前記複数の無線送受信部の各々の遅延時間を算出することを特徴としている。
【００２３】
本発明の第１０の無線基地局システムは、前記第２〜６のいずれかの無線基地局システムにおいて、
無線基地局システムが処理する伝送データが、ＣＤＭＡ方式により多重化されたことを特徴としている。
【００２４】
【発明の実施の形態】
次に、本発明の実施の形態について図面を参照して説明する。
【００２５】
図１は本発明の無線基地局システムの一つの実施の形態を示すブロック図である。
【００２６】
図１に示す本実施の形態は、遠方の無線送受信部１０１と通信接続される無線基地局装置１と、無線送受信部１０１に通信接続される無線送受信部１０２と、無線送受信部１０２に通信接続され以降の無線送受信部は同様にカスケード接続される無線送受信部１０Ｎとから構成されている。
【００２７】
図２は図１の無線基地局装置の一例を示す詳細ブロック図である。
【００２８】
図２を参照すると無線基地局装置１は、遠方の無線送受信部への送信合成信号２１を出力し、かつ遠方の無線送受信部からの受信合成信号７１を入力しデータ処理を行うデータ処理部２０１と、無線送受信部への送信合成信号２２を出力し、かつ無線送受信部からの受信合成信号７２を入力しデータの処理を行うデータ処理部２０２と、同様に各無線送受信部への送信合成信号２Ｎを出力し、かつ受信合成信号７Ｎを入力しデータの処理を行うデータ処理部２０Ｎと、データ処理部２０１，２０２，２０Ｎからの送信合成信号２１，２２，２Ｎを入力してそれぞれ拡散処理を行う拡散部２と、拡散部２から出力される送信合成信号３１，３２，３Ｎを入力し、これらを多重して送信多重信号４１を出力する多重部３と、多重部３から出力された送信多重信号４１の電気信号を光信号に変換して、無線送受信部１０１に送信多重化信号４２として出力する電気／光変換部４と、無線送受信部１０１からの受信多重化信号４３を入力して、この光信号を電気信号に変換し受信多重信号４４として出力する光／電気変換部５と、光／電気変換部５から出力された受信多重信号４４を入力して逆拡散し、受信合成信号７１，７２，７Ｎに分離出力する逆拡散部６と、拡散部２から送信合成信号３１，３２，３Ｎの拡散タイミング信号８１及び逆拡散部６から受信合成信号７１，７２，７Ｎの逆拡散タイミング信号８２を入力し、送受信信号の遅延時間を測定する遅延測定部７とから構成されている。
【００２９】
図３は図１の無線送受信部の一例を示す詳細なブロック図である。
【００３０】
図３を参照すると、無線基地局装置１から出力された送信多重化信号４２を入力し、光信号を電気信号に変換する光／電気変換部８と、光／電気変換部８が出力した送信多重信号４５を入力し、この送信多重信号４５を２分配して送信多重信号４６および送信多重信号４７を出力する分離部９と、分離部９が出力した一方の送信多重信号４６の電気信号を光信号に変換し無線送受信部１０２に出力する電気／光変換部１０と、分離部９が出力した他方の送信多重信号４７を入力し、逆拡散により必要な送信合成信号４８のみ抽出して出力し、かつ逆拡散タイミング信号４９を出力する逆拡散部１１と、逆拡散部１１が出力した送信合成信号４８を入力して、送信ベ−スバンド信号と制御信号を分離し、送信ベースバンド信号をデジタル・アナログ変換及び周波数変換し、送信無線信号５１として出力する送信無線処理部１２と、送信無線処理部１２から出力された送信無線信号５１を入力し出力するサーキュレータ部１３と、サーキュレータ部１３から出力された送信無線信号を外部へ送信し、かつ外部からの受信無線信号を受信するアンテナ部１４と、アンテナ部１４およびサーキュレータ部１３からの受信無線信号５２を周波数変換およびアナログ・デジタル変換した受信ベースバンド信号を生成し、この受信ベースバンド信号と制御信号を合成することで、受信合成信号５３を出力する受信無線処理部１５と、この受信無線処理部１５が出力した受信合成信号５３と逆拡散部１１から出力された逆拡散タイミング信号４９を入力し、拡散処理を行い受信合成信号５４を出力する拡散部１６と、無線送受信部１０２からの光信号を電気信号に変換し受信多重化信号５５として出力する光／電気変換部１７と、拡散部１６が出力した受信合成信号５４および光／電気変換部１７が出力した受信多重化信号５５を多重化し受信多重化信号５６として出力する多重部１８と、多重部１８が出力した受信多重化信号５６の電気信号を光信号に変換し無線基地局装置１に出力する電気／光変換部１９とから構成されている。
【００３１】
なお、無線送受信部１０２及び他の各無線送受信部の構成も無線送受信部１０１と同様の構成である。
【００３２】
次に本発明の実施の形態について図１を参照して詳細に説明する。
【００３３】
ここでは特に、移動通信で使用されているＷ−ＣＤＭＡ（Ｗｉｄｅｂａｎｄ−ＣｏｄｅＤｉｖｉｓｉｏｎＭｕｌｔｉｐｌｅＡｃｃｅｓｓ）方式の無線基地局装置（チップレート３．８４Ｍｂｐｓ）に対して説明する。
【００３４】
また、無線基地局装置１と各無線送受信部間及び無線送受信部と他の無線送受信部との間は、長距離伝送に適した光ファイバを使用して光シリアル伝送させるものとする。さらに無線基地局装置１は、送受信各一本の光ファイバで８つの無線送受信部が接続されており、無線基地局装置１から最も遠距離にある無線送受信部１０Ｎまでの送受信を含めた光ファイバの最大遅延時間を０．８ｍｓである場合を例として説明する。
【００３５】
従って、無線基地局装置１は図２の構成に加えて図示はしないが、上位装置とのインタフェースを行なう上位インタフェース部と、誤り訂正符号／復号部と、フレーム化部と、データ変調／復調部と、Ｗ−ＣＤＭＡ方式としての拡散／逆拡散を行なうベースバンド信号処理部と、上位インタフェース部とベースバンド信号処理部を制御する制御部と、無線送受信部１０１とのインタフェースを行なう光インタフェース部とが含まれる。
【００３６】
一方無線送受信部１０１〜１０Ｎは図３の構成に加えて図示はしないが、無線基地局装置１及び他の無線送受信部１０１〜１０Ｎとのインタフェースを行なう光インタフェース部と、ベースバンド信号／無線周波数信号の変換を行ない端末装置とのインタフェースを行なう無線部と、無線部を制御する制御部とが含まれている。
【００３７】
次に、図２および図３を参照して送信信号の流れについて説明する。
【００３８】
無線基地局装置１のデータ処理部２０１は、無線送受信部１０１に出力される送信ベースバンド信号と送信制御信号を時分割多重した送信合成信号２１を拡散部２に出力する。データ処理部２０２〜２０Ｎも同様に、無線送受信部１０２〜１０Ｎに出力される送信ベースバンド信号と送信制御信号をそれぞれ時分割多重した送信合成信号２２および送信合成信号２Ｎを拡散部２に出力する。
【００３９】
図４はベースバンド信号及び送信制御信号の多重方法の一例を示す図である。
【００４０】
ここで送信ベースバンド信号と送信制御信号の多重方法の一例を図４を用いて説明する。
【００４１】
まず１単位をフレームとし、フレームの先頭に同期コードを付加する。同期コードは、送信するベースバンド信号と送信する制御信号のデータ位置を検出するために使用される。同期コードの次の時間には制御信号を付加する。制御信号は、無線送受信部の各種の設定や状態監視を行なうために使用される。
【００４２】
また、制御信号の次の時間にはベースバンド信号を付加する。ベースバンド信号は、送信ダイバーシチ有の場合、０系／１系からなり、それぞれＩ／Ｑの振幅データ情報で構成されている。Ｗ−ＣＤＭＡシステムで要求されるダイナミックレンジや電力制御精度の確保のため、通常それぞれ１ｂｙｔｅ（８ｂｉｔ）以上のｂｙｔｅ数が必要になる。ここでは、それぞれ０系／１系、Ｉ／Ｑの振幅それぞれに２ｂｙｔｅを割り当てる。すなわち１グループとしては８ｂｙｔｅの情報が必要である。なお、実際のデータの挿入は光インタフェース間の多重によるダイナミックレンジを考慮する。８多重を考えた場合は、２Ｂｙｔｅ（１６ｂｉｔ）あたり１３ｂｉｔ程度とすることにより、
１３ｂｉｔ×８＜１６ｂｉｔ
となるので、多重データをオーバーフローさせることなく伝送できる。
【００４３】
以上のことから、送信ベースバンド信号を伝送するのに必要とされる伝送レートは、
３．８４Ｍｂｐｓ×（８×８）ｂｉｔ＝２４５．７６Ｍｂｐｓ
となる。なお、送信するベースバンド信号は振幅データのため、連続送信が必要であり、送信合成信号の伝送速度は送信するベースバンド信号の伝送速度と公約数が存在する必要がある。
【００４４】
また、送信するベースバンド信号は制御信号と比較してデータ量が大きいため、１フレームあたり同期コード２ｂｙｔｅ、送信制御信号６ｂｙｔｅ、送信ベースバンド信号５１２ｂｙｔｅというように割り当てる（合計５２０ｂｙｔｅ）。この場合、送信合成信号を伝送するのに必要とされる伝送レートは、
２４５．７６Ｍｂｐｓ×（５２０／５１２）＝２４９．６Ｍｂｐｓ
となる。次に拡散部２に入力されたデータ処理部２０１〜２０Ｎを出力した８つの送信合成信号は、それぞれに２種類の拡散コードを割り当てて拡散させる。拡散率は８つの送信合成信号３１，３２，３Ｎを合成するため「８」とする。
【００４５】
図５は拡散部及び逆拡散部で使用する拡散コードの一例を示す図である。
【００４６】
第一の拡散コードは、図５に示されている８つのコードを別々に割り当てる。理由は、受信側で８つの送信合成信号３１，３２，３Ｎを分離するためである。第二の拡散コードは自己相関性の高い最長符号系列（Ｍ系列）等により周期的なコードとし、送受信含めた光ファイバの遅延時間よりも長い周期のコードを使用する。ここでは１ｍｓと仮定する。
【００４７】
第二の拡散コードは８つの送信合成信号３１，３２，３Ｎに同じ符号を割り当ててもよいが、同時刻に同パターンの符号系列を割り当てると多重した場合に相互相関性が悪化するため、それぞれの時間をオフセットさせるとよい。この第二のコードは遅延時間を測定するために利用される。
【００４８】
なお、拡散後の送信合成信号を伝送するのに必要とされる伝送レートは、拡散率が８のために８倍に拡散されて、
２４９．６Ｍｂｐｓ×８倍＝１．９９６８Ｇｂｐｓ
となる。その後、拡散された送信合成信号３１，３２，３Ｎは、多重部３に出力される。
【００４９】
図６は伝送フォーマットを拡散した場合の一例を示す図である。
【００５０】
なお、図６は拡散した後のデータを示した図であり、本例の場合は２ｂｙｔｅ単位に拡散した場合の例である。８つの送信合成信号３１，３２，３Ｎを拡散するため、拡散前は１／１５．６ＭＨｚであった伝送速度が、拡散後は１／１２４．８ＭＨｚ（８倍）となる。
【００５１】
次に、多重部３に入力された８つの送信合成信号３１，３２，３Ｎは多重され、送信多重信号４１として電気／光変換部４に出力される。多重方法はＣＤＭＡ方式を用いコード多重させることにより、伝送レートは変わらずに多重される。
【００５２】
電気／光変換部４に入力される送信多重信号４１は、パラレルデータをシリアルデータに変換した後、電気から光信号に変換される。光信号に変換された送信多重化信号４２は、光ファイバを経由して無線送受信部１０１に出力される。
【００５３】
また、光ファイバの伝送は通常８Ｂ／１０Ｂエンコード／デコードにより、８／１０ｂｉｔに変換して、１０ｂｉｔのシリアル伝送を行なう。
従って、光ファイバを伝送するのに必要とされる伝送レートは、
１．９９６８Ｇｂｐｓ×１０／８＝２．４９６Ｇｂｐｓ
となる。
【００５４】
次に、無線基地局装置１が出力した送信多重化信号４２は、図３の無線送受信部１０１の光／電気変換部８に入力される。ここで送信多重化信号４２は光信号から電気信号に変換された後、シリアルデータからパラレルデータに変換され、分離部９に出力される。通常のデシリアライザ（パラレルデータからシリアルデータに変換）は送信側のシリアルデータに同期したクロックを抽出できるため、このクロックを無線送受信部１０１の基準クロックとすることにより、無線基地局装置１と無線送受信部１０１とは周波数同期をとることができる。
【００５５】
分離部９に入力されたパラレルデータに変換された送信多重信号４５は、無線基地局装置１の基準クロックから無線送受信部１０１の基準クロックに変換するためにリタイミングされた後、一方は電気／光変換部１０に出力され、他方は逆拡散部１１に出力される。電気／光変換部１０に入力された一方の送信多重信号４６は、パラレルデータからシリアルデータに変換された後光信号に変換され、無線送受信部１０２へ出力される。逆拡散部１１に入力された他方の送信多重信号４７は逆拡散され、必要な送信合成信号のみが抽出され送信合成信号４８として送信無線処理部１２に出力される。
【００５６】
なお、具体的にはまず第二の拡散コードにより逆拡散させ、その後予め各無線送受信部とコード番号の関係を決めておく。このことにより、データ処理部２０１で生成された送信合成信号２１が図５のコード１（第一の拡散コード）で拡散されていた場合は、コード１を用いて逆拡散することによりデータ処理部２０１で生成された送信合成信号２１のみを抽出することが可能である。また、第二の拡散コードの先頭（１ｍｓ周期の先頭）を逆拡散により算出し、タイミング信号として拡散部１６に出力される。送信無線処理部１２に入力された送信合成信号４８は、同期コードを使用し送信制御信号と送信ベースバンド信号を分離する。
【００５７】
次に、送信ベースバンド信号は、デジタル／アナログ変換および周波数変換がされ、送信無線信号５１としてサーキュレータ部１３に出力される。また、送信制御信号により、各種設定や状態監視を行なう。
【００５８】
サーキュレータ部１３に入力された送信無線信号５１は、アンテナ部１４に出力されるが、受信無線処理部１５には出力されない。アンテナ部１４に入力された送信無線信号は、外部端末装置へ送信される。
【００５９】
なお、図１の無線送受信部１０２〜１０Ｎの動作も、それぞれ無線送受信部１０１〜１０Ｎから出力された送信多重信号を入力として、無線送受信部１０１と同様の動作をする。
【００６０】
次に、受信信号の流れについて説明する。
【００６１】
外部の端末装置から送信された無線信号は、図３のアンテナ部１４に入力される。アンテナ部１４に入力された無線信号は、サーキュレータ部１３に出力される。サーキュレータ部１３に入力された無線信号は、受信無線処理部１５に受信無線信号５２として出力されるが、送信無線処理部１２には出力されない。受信無線処理部１５に入力された受信無線信号５２は、周波数変換され、アナログ／デジタル変換され、受信ベースバンド信号となる。
【００６２】
また、無線基地局装置１への各種の設定応答や状態監視応答を行なう受信制御信号を生成する。その後、受信制御信号と、受信ベースバンド信号の合成を行なう。合成方法は送信側と同様に、同期コードを付加し、受信合成信号５３を生成し、拡散部１６に出力される。拡散部１６に入力された受信合成信号５３は、無線送受信部１０１と同様に２種類の拡散コードを割り当て拡散させる。
【００６３】
第一の拡散コードは、図５のコード１を割り当てる。次に、第二の拡散コードは、逆拡散部１１から出力された逆拡散タイミング信号８２の位置を拡散コードの先頭（１ｍｓ周期の先頭）として拡散させる。
【００６４】
拡散後のデータは送信側と同様に図６に示すように、拡散前は１／１５．６ＭＨｚであった伝送速度が拡散後は１／１２４．８ＭＨｚ（８倍）となる。その後拡散部１６で、拡散された受信合成信号５４は、多重部１８に出力される。
一方、無線送受信部１０２からの受信信号は、光／電気変換部１７に入力され光から電気信号に変換された後、シリアルデータからパラレルデータに変換され、受信多重化信号５５として多重部１８に出力される。拡散部１６が出力した受信合成信号５４と光／電気変換部１７が出力した受信多重化信号５５は、多重部１８で多重化され、受信多重信号５６として電気／光変換部１９に出力される。
【００６５】
なお、多重方法はＣＤＭＡ方式を用いコード多重させることにより、伝送レートは変わらずに多重化される。電気／光変換部１９に入力された受信多重化信号５６は、パラレルデータをシリアルデータに変換した後、電気から光信号に変換される。光信号に変換された受信多重化信号５６は、光ファイバを経由して無線基地局装置１に出力される。なお、無線送受信部１０２〜１０Ｎの動作も、それぞれ無線送受信部１０２〜１０Ｎから出力された受信多重信号を入力として、無線送受信部１０１と同様の動作をする。
【００６６】
次に、無線送受信部１０２からの受信多重化信号４３は、図２の光／電気変換部５に入力される。ここで受信多重化信号４３は光から電気信号に変換された後、シリアルデータからパラレルデータに変換され逆拡散部６に出力される。逆拡散部６に入力された受信多重信号４４は逆拡散され、８つの受信合成信号７１，７２，７Ｎが抽出され、それぞれのデータ処理部２０１〜２０Ｎに出力される。
【００６７】
なお、具体的にはまず第二の拡散コードにより逆拡散させる。その後それぞれの無線送受信部１０１〜１０Ｎで生成された受信合成信号７１，７２，７Ｎは、図５のコード１〜８（第一の拡散コード）で拡散されているため、コード１〜８を用いて逆拡散することにより、それぞれの無線送受信部１０１〜１０Ｎで生成された受信合成信号７１，７２，７Ｎを抽出することが可能である。また、第二の拡散コードの先頭（１ｍｓ周期の先頭）を逆拡散により算出し、逆拡散タイミング信号８２として遅延測定部７に出力される。それぞれのデータ処理部２０１〜２０Ｎに入力された受信合成信号７１，７２，７Ｎは、受信ベースバンド信号と受信制御信号に分離される。受信ベースバンド信号は、ベースバンド信号処理部（図示せず）に出力される。また、受信制御信号は、無線送受信部１０１〜１０Ｎの各種設定応答や監視応答を処理する。
【００６８】
図７は遅延測定部の遅延時間測定のタイムチャートを示す図である。
【００６９】
また、拡散部２から拡散タイミング信号８１と、逆拡散部６から逆拡散タイミング信号８２を入力した遅延測定部７は、図７に示すように、それぞれの無線送受信部１０１〜１０Ｎに送信した第二の拡散コードの先頭（１ｍｓ周期の先頭）と、それぞれの無線送受信部１０１〜１０Ｎから受信した第二の拡散コードの先頭（１ｍｓ周期の先頭）との差から送受信光ファイバ遅延を算出でき、この送受信光ファイバ遅延を１／２とすることにより、無線基地局装置１とそれぞれの無線送受信部１０１〜１０Ｎの遅延時間を算出することができる。このときの遅延時間の精度は図６に示す拡散単位により、この例の場合は、１／１２４．８ＭＨｚ（約３／１００ｃｈｉｐ）の精度を得ることができる。
【００７０】
また、運用中に遅延時間を測定したい場合にも、制御信号及びベースバンド信号内に遅延時間測定のためのデータを挿入する必要がないため、システムを通常運用させながら測定が可能となる。
【００７１】
図８は伝送フォーマットを拡散した場合の他の一例を示す図である。
【００７２】
本発明の他の実施例として、図８に示すように、８つの無線送受信部が接続された状態で、８ｂｉｔ毎に拡散させた場合は、１／２４９．６ＭＨｚ（約４／１０００ｃｈｉｐ）の精度を得ることができる。
【００７３】
上述の通り、送受信アンテナが複数個遠方にある無線基地局システムにおいて、無線基地局装置と送受信アンテナ間の伝送信号をデジタル信号とし、送信側で複数の送受信アンテナのデジタル信号をＣＤＭＡ方式により多重し、受信側で複数の送受信アンテナのデジタル信号を分離することにより、既存のサービスを停止することなく無線基地局装置と送受信アンテナ間の遅延時間を高精度に測定できることになる。
【００７４】
【発明の効果】
以上説明したように、本発明の無線基地局システムは、無線基地局装置と送受信アンテナ間の遅延時間を高精度で測定でき、かつ運用中に遅延時間の測定ができるので、経年変化等で遅延量が変化した場合にもサービスを停止させることなく遅延時間が測定できる無線基地局システムを供給できるという効果を有している。
【図面の簡単な説明】
【図１】本発明の無線基地局システムの一つの実施の形態を示すブロック図である。
【図２】図１の無線基地局装置の一例を示す詳細ブロック図である。
【図３】図１の無線送受信部の一例を示す詳細ブロック図である。
【図４】ベースバンド信号及び送信制御信号の多重方法の一例を示す図である。
【図５】拡散部及び逆拡散部で使用する拡散コードの一例を示す図である。
【図６】伝送フォーマットを拡散した場合の一例を示す図である。
【図７】遅延測定部の遅延時間測定のタイムチャートを示す図である。
【図８】伝送フォーマットを拡散した場合の他の一例を示す図である。
【図９】従来の時分割方式での伝送フォーマットを示す図である。
【符号の説明】
１無線基地局装置
２拡散部
３多重部
４電気／光変換部
５光／電気変換部
６逆拡散部
７遅延測定部
８光／電気変換部
９分離部
１０電気／光変換部
１１逆拡散部
１２送信無線処理部
１３サーキュレータ部
１４アンテナ部
１５受信無線処理部
１６拡散部
１７光／電気変換部
１８多重部
１９電気／光変換部
２１，２２，２Ｎ送信合成信号
３１，３２，３Ｎ送信合成信号
４１送信多重信号
４２送信多重化信号
４３受信多重化信号
４４受信多重信号
４５，４６，４７送信多重信号
４８送信合成信号
４９逆拡散タイミング信号
５１送信無線信号
５２受信無線信号
５３，５４受信合成信号
５５，５６受信多重化信号
７１，７２，７Ｎ受信合成信号
８１拡散タイミング信号
８２逆拡散タイミング信号
１０１，１０２，１０Ｎ無線送受信部
２０１，２０２，２０Ｎデータ処理部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radio base station system, and in particular, multiplexes a transmission signal between a radio base station apparatus and a distant radio transmission / reception section by a CDMA system, and stops a radio base station apparatus and a distant radio transmission / reception section without stopping existing services. The present invention relates to a radio base station system capable of measuring a delay time with respect to a radio base station with high accuracy.
[0002]
[Prior art]
Generally, in a wireless base station system having a plurality of transmitting and receiving antennas at a distance, signals of the respective transmitting and receiving antennas are multiplexed by a time division multiplexing method.
[0003]
FIG. 9 is a diagram showing a transmission format in a conventional time division system.
[0004]
When trying to measure the delay time by such a time division method, for example, in a system that supports eight transmitting and receiving antennas for antennas 1 to 8, as shown in FIG. Since it is 1/8 of the entire time, the accuracy of measuring the delay amount is only in units of 1/8.
[0005]
In this example, all data for the transmitting and receiving antennas 1 to 8 are allocated to control signals for measuring the amount of delay, and if the amount of delay is to be measured again during operation, the baseband signal is stopped. It is necessary to temporarily stop the service in operation.
[0006]
In the adjustment of the delay time, the delay time is measured using a delay time measuring device, and the delay time variable request is adjusted based on the measurement result.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless base station system in which a plurality of transmitting and receiving antennas are distant, a digital transmission signal between the wireless base station apparatus and the distant wireless transmitting and receiving unit transmitting and receiving antennas, A digital signal is multiplexed by a CDMA (Code Division Multiple Access) method, and a digital signal of a plurality of transmitting and receiving antennas is separated on a receiving side, so that existing services are not stopped, and a remote transmitting and receiving unit with a wireless base station apparatus is transmitted and received. It is an object of the present invention to provide a radio base station system capable of measuring a delay time between antennas with high accuracy.
[0008]
In a conventional wireless base station system, a signal of each element of a variable directional antenna of a base station is time-division-multiplexed by a time-division multiplexing device, and the time-division multiplexed signal is transmitted in the same optical fiber, so that each antenna is transmitted. The relative position change between the elements is eliminated, and the relative phase difference between the elements of the antenna is maintained (for example, see Patent Document 1).
[0009]
Also, a transmitting / receiving device is installed at the centralized base station, a transmitting / receiving antenna is installed at the wireless base station, a connection is established between the wireless base station and the centralized base station via a transmission line, and signals between the transmitting / receiving device and the transmitting / receiving antenna are transmitted. There is also a base station apparatus including a full-duplex base station transmission path for monitoring the state of the transmission path (for example, see Patent Document 2).
[0010]
[Patent Document 1]
JP-A-2001-94332 (pages 3 to 5, FIGS. 1 and 2)
[Patent Document 2]
JP-A-5-327632 (page 2-3, FIG. 1)
[0011]
[Problems to be solved by the invention]
In the above-described conventional radio base station system, when trying to measure the delay time by such a time division method, the time allocated to each transmitting and receiving antenna is 1/8 of the entire time. However, there is a disadvantage that there is no accuracy in measuring the amount of delay.
[0012]
Further, when all data for the transmitting and receiving antennas 1 to 8 are allocated to control signals for measuring the amount of delay, if it is necessary to measure the amount of delay again during operation, it is necessary to stop the baseband signal. There is a drawback in that it is necessary to temporarily stop the service in operation.
[0013]
SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless base station system in which a plurality of wireless transmitting / receiving sections having transmitting / receiving antennas are distant, a digital transmission signal between the wireless base station apparatus and the transmitting / receiving antenna of the wireless transmitting / receiving section, The digital signal of the transmitting / receiving antenna is multiplexed by the CDMA method, and the receiving side separates the digital signals of the transmitting / receiving antennas, so that the existing service is not stopped, and the wireless base station apparatus and the remote transmitting / receiving antenna It is an object of the present invention to provide a radio base station system capable of measuring a delay time with respect to the base station with high accuracy.
[0014]
[Means for Solving the Problems]
A first wireless base station system according to the present invention is a wireless base station system in which a plurality of wireless base station devices and a plurality of transmitting and receiving antennas are distant,
A transmission signal between the radio base station apparatus and the transmission / reception antenna is a digital signal, digital signals of the plurality of transmission / reception antennas are multiplexed on a transmission side by a CDMA (Code Division Multiple Access) method, and a plurality of transmission / reception antennas are received on a reception side. The delay time between the radio base station apparatus and the transmitting / receiving antenna is measured by separating the digital signals of
[0015]
A second wireless base station system of the present invention includes:
A wireless base station device, comprising a plurality of remote cascade-connected wireless transmitting and receiving units for communication connection with the wireless base station device;
The wireless base station device,
A plurality of first transmission combined signals are respectively output to the plurality of distant wireless transmission / reception units, and a plurality of reception combined signals from the plurality of distant wireless transmission / reception units are input, and each performs data processing. A plurality of data processing units;
A spreading unit that receives the plurality of first transmission combined signals from the plurality of data processing units, performs spreading processing, and outputs a plurality of second transmission combined signals;
A multiplexing unit that inputs the plurality of second transmission combined signals output from the spreading unit, multiplexes the second combined transmission signals, and outputs a transmission multiplexed signal;
An electrical / optical converter that converts an electrical signal of the transmission multiplex signal output from the multiplexing unit into an optical signal and outputs the optical signal as a transmission multiplexed signal to the wireless transmission / reception unit;
An optical / electrical conversion unit that receives a reception multiplexed signal from the wireless transmission / reception unit, converts the optical signal into an electric signal, and outputs the electric signal as a reception multiplexed signal;
A despreading unit that inputs and despreads the received multiplexed signal output from the optical / electrical conversion unit and separates and outputs the plurality of received combined signals;
Delay measurement for receiving a spread timing signal of the plurality of second transmission combined signals from the spreading unit and a despread timing signal of the plurality of reception combined signals from the despreading unit and measuring a delay time of a transmission / reception signal Department and;
It is characterized by having.
[0016]
A third wireless base station system according to the present invention includes:
A wireless base station device, comprising a plurality of remote cascade-connected wireless transmitting and receiving units for communication connection with the wireless base station device;
The wireless transmitting and receiving unit,
A first optical / electrical conversion unit that receives a transmission multiplexed signal output from the wireless base station apparatus and converts an optical signal into an electric signal;
A separation unit that receives the transmission multiplex signal output by the first optical / electrical conversion unit, divides the transmission multiplex signal into two, and outputs a first transmission multiplex signal and a second transmission multiplex signal;
A first electrical / optical converter that converts the electrical signal of the first transmission multiplex signal output by the demultiplexer into an optical signal and outputs the optical signal to the wireless transceiver;
A despreading unit that receives the second transmission multiplexed signal output by the demultiplexing unit, extracts and outputs a required transmission combined signal by despreading, and outputs a despreading timing signal;
A transmission radio for receiving the transmission composite signal output by the despreading unit, separating a transmission baseband signal and a control signal, performing digital / analog conversion and frequency conversion on the transmission baseband signal, and outputting the converted signal as a transmission radio signal. Processing unit;
A circulator section for inputting and outputting the transmission radio signal output from the transmission radio processing section;
An antenna unit for transmitting a radio signal output from the circulator unit to the outside and receiving a radio signal from the outside;
By generating a reception baseband signal obtained by performing frequency conversion and analog-to-digital conversion on the reception radio signal from the antenna unit and the circulator unit, and synthesizing the reception baseband signal and the control signal, a first reception synthesis signal is obtained. A receiving wireless processing unit for outputting;
A spreading unit that receives the first received combined signal output from the receiving wireless processing unit and the despread timing signal output from the despreading unit, performs spreading processing, and outputs a second received combined signal;
A second optical / electrical conversion unit that converts an optical signal from the wireless transmission / reception unit into an electric signal and outputs the electric signal as a first reception multiplexed signal;
A multiplexing unit that multiplexes the second received combined signal output by the spreading unit and the first received multiplexed signal output by the second optical / electrical converter, and outputs the multiplexed signal as a second received multiplexed signal When;
A second electrical / optical converter that converts the electrical signal of the second multiplexed signal output by the multiplexer into an optical signal and outputs the optical signal to the wireless base station apparatus;
It is characterized by having.
[0017]
A fourth wireless base station system according to the present invention, in the second or third wireless base station system,
Optical serial transmission is performed between the wireless base station device and the wireless transmission / reception unit and between the wireless transmission / reception unit and another wireless transmission / reception unit using an optical fiber suitable for long-distance transmission.
[0018]
A fifth radio base station system according to the present invention, in the fourth radio base station system,
The wireless base station apparatus is characterized in that eight of the wireless transmission / reception units are connected by one optical fiber for transmission / reception.
[0019]
A sixth radio base station system according to the present invention, in the second radio base station system,
Each of the plurality of data processing units included in the wireless base station device, the plurality of first transmission synthesized signals obtained by time division multiplexing a transmission baseband signal and a transmission control signal output to the wireless transmission / reception unit, It is characterized in that it is output to the diffusion unit.
[0020]
A seventh radio base station system according to the present invention, in the second radio base station system,
The eight second combined transmission signals input to the multiplexing unit of the wireless base station device are multiplexed without changing the transmission rate by code multiplexing using a CDMA (Code Division Multiple Access) method. , And is output to the electrical / optical converter as the transmission multiplexed signal.
[0021]
An eighth radio base station system according to the present invention, in the second or seventh radio base station system,
The transmission multiplex signal input to the electrical / optical conversion unit of the wireless base station device is obtained by converting parallel data into serial data, converting the electrical data into an optical signal, and converting the transmission multiplex signal into an optical signal. The converted signal is output to the wireless transmission / reception unit via an optical fiber.
[0022]
A ninth wireless base station system according to the present invention, in the second wireless base station system,
The delay measurement unit included in the wireless base station device,
The spreading timing signal from the spreading unit and the despreading timing signal from the despreading unit are input, and the head of the spreading code transmitted to each of the plurality of wireless transmitting and receiving units, and each of the plurality of wireless transmitting and receiving units The transmission / reception optical fiber delay is calculated from the difference from the head of the spread code received from the base station, and the delay time of each of the radio base station apparatus and the plurality of radio transmission / reception units is calculated.
[0023]
The tenth radio base station system of the present invention is the radio base station system according to any one of the second to sixth radio base stations,
The transmission data processed by the wireless base station system is multiplexed by the CDMA method.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0025]
FIG. 1 is a block diagram showing one embodiment of the radio base station system of the present invention.
[0026]
The present embodiment shown in FIG. 1 includes a radio base station apparatus 1 communicatively connected to a distant radio transmitting / receiving section 101, a radio transmitting / receiving section 102 communicatively connected to the radio transmitting / receiving section 101, and a communicative connection to the radio transmitting / receiving section 102. The subsequent wireless transmission / reception unit is similarly configured with a wireless transmission / reception unit 10N cascaded.
[0027]
FIG. 2 is a detailed block diagram showing an example of the wireless base station device of FIG.
[0028]
Referring to FIG. 2, a radio base station apparatus 1 outputs a transmission combined signal 21 to a distant wireless transmission / reception unit and inputs a reception combined signal 71 from a distant wireless transmission / reception unit to perform data processing. And a data processing unit 202 that outputs a transmission combined signal 22 to the wireless transmission / reception unit and inputs a reception combined signal 72 from the wireless transmission / reception unit to perform data processing, and similarly, a transmission combined signal to each wireless transmission / reception unit. 2N, and a data processing unit 20N for inputting the received combined signal 7N and processing the data, and a transmission combined signal 21, 22, 2N from the data processing units 201, 202, 20N to perform spreading processing, respectively. Spreading section 2 for performing transmission, combined transmission signals 31, 32 and 3N output from spreading section 2, multiplexing these and outputting transmission multiplexed signal 41, and output from multiplexing section 3 The electric / optical conversion unit 4 that converts the electric signal of the transmission multiplex signal 41 into an optical signal and outputs it as a transmission multiplex signal 42 to the radio transmission / reception unit 101 and the reception multiplex signal 43 from the radio transmission / reception unit 101 are input. Then, the optical / electrical converter 5 which converts the optical signal into an electric signal and outputs it as a received multiplexed signal 44, and the received multiplexed signal 44 output from the optical / electrical converter 5 are despread by inputting and receiving and combining. A despreading unit 6 that separates and outputs the signals 71, 72, and 7N; a spreading timing signal 81 of the transmission combined signals 31, 32, and 3N from the spreading unit 2 and a despreading of the reception combined signals 71, 72, and 7N from the despreading unit 6 It comprises a delay measuring section 7 which receives the timing signal 82 and measures the delay time of the transmission / reception signal.
[0029]
FIG. 3 is a detailed block diagram showing an example of the wireless transmission / reception unit of FIG.
[0030]
Referring to FIG. 3, a transmission multiplexed signal 42 output from the wireless base station apparatus 1 is input, and an optical / electrical conversion unit 8 for converting an optical signal into an electric signal, and a transmission output from the optical / electrical conversion unit 8 The multiplexed signal 45 is input, the transmission multiplexed signal 45 is split into two, and the transmission multiplexed signal 46 and the transmission multiplexed signal 47 are output. The electrical / optical converter 10 that converts the signal into an optical signal and outputs the signal to the wireless transmitter / receiver 102 and the other transmission multiplexed signal 47 output by the separator 9 are input, and only the necessary transmission combined signal 48 is extracted and output by despreading. A despreading unit 11 that outputs a despreading timing signal 49 and a transmission combined signal 48 output by the despreading unit 11 are input to separate a transmission baseband signal and a control signal, and to transmit a transmission baseband signal. Digital Ana A transmission radio processing unit 12 that performs a frequency conversion and frequency conversion and outputs the transmission radio signal 51, a circulator unit 13 that inputs and outputs the transmission radio signal 51 output from the transmission radio processing unit 12, and a circulator unit 13 that outputs the transmission radio signal 51. Unit 14 for transmitting the transmitted radio signal to the outside and receiving the received radio signal from the outside, and a reception baseband obtained by frequency-converting and analog-digital-converting the radio signal 52 received from the antenna unit 14 and the circulator unit 13 A reception radio processing unit 15 that generates a signal and combines the reception baseband signal and the control signal to output a reception synthesis signal 53; a reception synthesis signal 53 output by the reception radio processing unit 15 and a despreading unit; The despreading timing signal 49 output from 11 is input, spread processing is performed, and the received combined signal 54 is output. A spreading unit 16, an optical / electrical converting unit 17 which converts an optical signal from the wireless transmitting / receiving unit 102 into an electric signal and outputs it as a reception multiplexed signal 55, a received combined signal 54 output by the spreading unit 16 and an optical / electrical conversion A multiplexing unit 18 that multiplexes the reception multiplexed signal 55 output by the unit 17 and outputs the multiplexed signal as a reception multiplexed signal 56; and a radio base station apparatus that converts an electric signal of the reception multiplexed signal 56 output by the multiplexing unit 18 into an optical signal. And an electrical / optical conversion unit 19 for outputting the signal to the output unit 1.
[0031]
The configurations of the wireless transmission / reception unit 102 and the other wireless transmission / reception units are the same as those of the wireless transmission / reception unit 101.
[0032]
Next, an embodiment of the present invention will be described in detail with reference to FIG.
[0033]
Here, a radio base station apparatus (chip rate of 3.84 Mbps) of the W-CDMA (Wideband-Code Division Multiple Access) system used in mobile communication will be particularly described.
[0034]
Optical serial transmission is performed between the wireless base station device 1 and each wireless transmitting / receiving unit and between the wireless transmitting / receiving unit and another wireless transmitting / receiving unit using an optical fiber suitable for long-distance transmission. Further, the wireless base station apparatus 1 has eight wireless transceivers connected by one optical fiber for transmission and reception, and includes an optical fiber including transmission and reception from the wireless base station apparatus 1 to the wireless transceiver 10N at the farthest distance. The case where the maximum delay time is 0.8 ms will be described as an example.
[0035]
Therefore, although not shown in addition to the configuration of FIG. 2, the radio base station apparatus 1 has an upper interface section for interfacing with an upper apparatus, an error correction code / decoding section, a framing section, and a data modulation / demodulation section. A baseband signal processing unit for performing spreading / despreading as a W-CDMA system, a control unit for controlling a higher-level interface unit and a baseband signal processing unit, and an optical interface unit for interfacing with the radio transmitting / receiving unit 101 Is included.
[0036]
On the other hand, the radio transmitting / receiving sections 101 to 10N are not shown in addition to the configuration of FIG. 3, but an optical interface section for interfacing with the radio base station apparatus 1 and the other radio transmitting / receiving sections 101 to 10N, a baseband signal / radio frequency A wireless unit that performs signal conversion and interfaces with a terminal device and a control unit that controls the wireless unit are included.
[0037]
Next, the flow of a transmission signal will be described with reference to FIGS.
[0038]
The data processing unit 201 of the radio base station apparatus 1 outputs to the spreading unit 2 a transmission composite signal 21 obtained by time-division multiplexing the transmission baseband signal and the transmission control signal output to the radio transmission / reception unit 101. Similarly, the data processing units 202 to 20N output to the spreading unit 2 the transmission combined signal 22 and the transmission combined signal 2N obtained by time-division multiplexing the transmission baseband signal and the transmission control signal output to the radio transmission / reception units 102 to 10N, respectively. .
[0039]
FIG. 4 is a diagram illustrating an example of a multiplexing method of a baseband signal and a transmission control signal.
[0040]
Here, an example of a method of multiplexing the transmission baseband signal and the transmission control signal will be described with reference to FIG.
[0041]
First, one unit is a frame, and a synchronization code is added to the beginning of the frame. The synchronization code is used to detect the data positions of the baseband signal to be transmitted and the control signal to be transmitted. A control signal is added at the time following the synchronization code. The control signal is used to perform various settings and status monitoring of the wireless transmission / reception unit.
[0042]
Further, a baseband signal is added at a time subsequent to the control signal. When there is transmission diversity, the baseband signal is composed of the 0 system / 1 system, and is composed of I / Q amplitude data information. In order to secure the dynamic range and the power control accuracy required in the W-CDMA system, usually, each byte needs a byte number of 1 byte (8 bits) or more. Here, 2 bytes are assigned to each of the 0 system / 1 system and the I / Q amplitude. That is, one group needs 8 bytes of information. The actual data insertion takes into account the dynamic range due to multiplexing between optical interfaces. When 8 multiplexing is considered, by setting about 13 bits per 2 bytes (16 bits),
13bit × 8 <16bit
Therefore, multiplexed data can be transmitted without overflowing.
[0043]
From the above, the transmission rate required to transmit the transmission baseband signal is:
3.84 Mbps × (8 × 8) bits = 245.76 Mbps
It becomes. Since the baseband signal to be transmitted is amplitude data, continuous transmission is required, and the transmission speed of the transmission composite signal needs to be the transmission speed of the baseband signal to be transmitted and a common divisor.
[0044]
Further, since the amount of data of the baseband signal to be transmitted is larger than that of the control signal, the base station allocates a synchronization code of 2 bytes, a transmission control signal of 6 bytes, and a transmission baseband signal of 512 bytes per frame (total of 520 bytes). In this case, the transmission rate required to transmit the transmission composite signal is
245.76 Mbps × (520/512) = 249.6 Mbps
It becomes. Next, the eight transmission combined signals output from the data processing units 201 to 20N input to the spreading unit 2 are spread by allocating two types of spreading codes respectively. The spreading factor is set to "8" to combine the eight transmission combined signals 31, 32, and 3N.
[0045]
FIG. 5 is a diagram illustrating an example of a spreading code used in the spreading unit and the despreading unit.
[0046]
The first spreading code separately allocates the eight codes shown in FIG. The reason is to separate the eight transmission combined signals 31, 32, 3N on the receiving side. The second spreading code is a periodic code using a longest code sequence (M sequence) having high autocorrelation, and a code having a period longer than the delay time of the optical fiber including transmission and reception is used. Here, 1 ms is assumed.
[0047]
In the second spreading code, the same code may be assigned to the eight transmission combined signals 31, 32, and 3N. However, if a code sequence of the same pattern is assigned at the same time, cross-correlation deteriorates when multiplexing is performed. Should be offset. This second code is used to measure the delay time.
[0048]
Note that the transmission rate required to transmit the spread synthesized signal is spread 8 times because the spreading factor is 8,
249.6 Mbps x 8 times = 1.9968 Gbps
It becomes. Thereafter, the spread transmission combined signals 31, 32, 3N are output to the multiplexing unit 3.
[0049]
FIG. 6 is a diagram showing an example of a case where the transmission format is spread.
[0050]
FIG. 6 is a diagram showing data after spreading, and in the case of this example, an example of a case where data is spread in units of 2 bytes. Since the eight transmission combined signals 31, 32, and 3N are spread, the transmission rate from 1 / 15.6 MHz before spreading is reduced to 1 / 14.8 MHz (8 times) after spreading.
[0051]
Next, the eight transmission combined signals 31, 32, 3N input to the multiplexing unit 3 are multiplexed and output to the electrical / optical conversion unit 4 as a transmission multiplexed signal 41. As a multiplexing method, code multiplexing is performed using the CDMA method, so that the transmission rate is multiplexed without change.
[0052]
The transmission multiplex signal 41 input to the electrical / optical conversion unit 4 converts parallel data into serial data, and then converts the electrical data into an optical signal. The transmission multiplexed signal 42 converted to an optical signal is output to the wireless transmission / reception unit 101 via an optical fiber.
[0053]
The transmission of the optical fiber is usually converted into 8/10 bits by 8B / 10B encoding / decoding, and serial transmission of 10 bits is performed.
Therefore, the transmission rate required to transmit an optical fiber is
1.9968 Gbps × 10/8 = 2.496 Gbps
It becomes.
[0054]
Next, the transmission multiplexed signal 42 output from the wireless base station device 1 is input to the optical / electrical converter 8 of the wireless transceiver 101 in FIG. Here, the transmission multiplexed signal 42 is converted from an optical signal to an electric signal, then converted from serial data to parallel data, and output to the demultiplexer 9. A normal deserializer (converting parallel data to serial data) can extract a clock synchronized with the serial data on the transmitting side. The unit 101 can be frequency-synchronized.
[0055]
The transmission multiplexed signal 45 converted into the parallel data input to the separation unit 9 is retimed to convert the reference clock of the radio base station apparatus 1 into the reference clock of the radio transmission / reception unit 101, and one of the transmission / reception signals is converted into an electric / electrical signal. The light is output to the light conversion unit 10, and the other is output to the despreading unit 11. One of the transmission multiplexed signals 46 input to the electrical / optical converter 10 is converted from parallel data to serial data, then converted to an optical signal, and output to the wireless transceiver 102. The other transmission multiplexed signal 47 input to the despreading unit 11 is despread, and only a required transmission combined signal is extracted and output to the transmission radio processing unit 12 as a transmission combined signal 48.
[0056]
Specifically, first, despreading is performed using a second spreading code, and then the relationship between each wireless transmission / reception unit and the code number is determined in advance. Accordingly, when the transmission composite signal 21 generated by the data processing unit 201 is spread by the code 1 (first spreading code) in FIG. 5, the data processing unit 201 performs despreading by using the code 1. It is possible to extract only the transmission composite signal 21 generated in 201. The head of the second spreading code (the head of the 1 ms period) is calculated by despreading, and is output to the spreading unit 16 as a timing signal. The transmission combined signal 48 input to the transmission wireless processing unit 12 uses a synchronization code to separate a transmission control signal and a transmission baseband signal.
[0057]
Next, the transmission baseband signal is subjected to digital / analog conversion and frequency conversion, and output to the circulator unit 13 as a transmission radio signal 51. Various settings and status monitoring are performed by the transmission control signal.
[0058]
The transmission radio signal 51 input to the circulator unit 13 is output to the antenna unit 14 but not output to the reception radio processing unit 15. The transmission radio signal input to the antenna unit 14 is transmitted to an external terminal device.
[0059]
The operation of the wireless transmission / reception units 102 to 10N in FIG. 1 also performs the same operation as that of the wireless transmission / reception unit 101 with the transmission multiplexed signals output from the wireless transmission / reception units 101 to 10N as inputs.
[0060]
Next, the flow of the received signal will be described.
[0061]
The wireless signal transmitted from the external terminal device is input to the antenna unit 14 in FIG. The radio signal input to the antenna unit 14 is output to the circulator unit 13. The radio signal input to the circulator unit 13 is output to the reception radio processing unit 15 as a reception radio signal 52, but is not output to the transmission radio processing unit 12. The reception radio signal 52 input to the reception radio processing unit 15 is subjected to frequency conversion, analog / digital conversion, and becomes a reception baseband signal.
[0062]
In addition, it generates a reception control signal for performing various setting responses and status monitoring responses to the wireless base station device 1. After that, the reception control signal and the reception baseband signal are combined. The combining method adds a synchronization code, generates a received combined signal 53, and outputs the combined signal to the spreading section 16 as in the transmitting side. The received combined signal 53 input to the spreading unit 16 is spread by allocating two types of spreading codes in the same manner as the wireless transmitting / receiving unit 101.
[0063]
As the first spreading code, code 1 in FIG. 5 is assigned. Next, the second spreading code spreads the position of the despreading timing signal 82 output from the despreading unit 11 as the head of the spreading code (the head of a 1 ms period).
[0064]
As shown in FIG. 6, similarly to the transmitting side, the transmission rate of the spread data is 1 / 15.6 MHz before spreading, but becomes 1 / 12.44.8 MHz (8 times) after spreading. Thereafter, the received combined signal 54 spread by the spreading unit 16 is output to the multiplexing unit 18.
On the other hand, a reception signal from the wireless transmission / reception unit 102 is input to the optical / electrical conversion unit 17 and converted from light to an electric signal, and then converted from serial data to parallel data. Is output. The reception combined signal 54 output from the spreading unit 16 and the reception multiplexed signal 55 output from the optical / electrical conversion unit 17 are multiplexed by the multiplexing unit 18 and output to the electrical / optical conversion unit 19 as a reception multiplexed signal 56. .
[0065]
The multiplexing method is multiplexing without changing the transmission rate by code multiplexing using the CDMA method. The reception multiplexed signal 56 input to the electrical / optical converter 19 converts parallel data into serial data, and then converts the electrical data into an optical signal. The received multiplexed signal 56 converted into an optical signal is output to the wireless base station device 1 via an optical fiber. The operations of the wireless transmission / reception units 102 to 10N are the same as the operations of the wireless transmission / reception unit 101, with the reception multiplexed signals output from the wireless transmission / reception units 102 to 10N as inputs.
[0066]
Next, the reception multiplexed signal 43 from the wireless transmission / reception unit 102 is input to the optical / electric conversion unit 5 in FIG. Here, the reception multiplexed signal 43 is converted from light to an electric signal, then converted from serial data to parallel data, and output to the despreading unit 6. The received multiplexed signal 44 input to the despreading unit 6 is despread, and eight received combined signals 71, 72, 7N are extracted and output to the respective data processing units 201 to 20N.
[0067]
Note that, specifically, first, despreading is performed using a second spreading code. Thereafter, the received combined signals 71, 72, and 7N generated by the wireless transmission / reception units 101 to 10N are spread by the codes 1 to 8 (first spreading codes) in FIG. By performing despreading, it is possible to extract the received combined signals 71, 72, and 7N generated by the wireless transmission / reception units 101 to 10N. Further, the head of the second spreading code (the head of the 1 ms period) is calculated by despreading, and is output to the delay measuring unit 7 as a despreading timing signal 82. The received combined signals 71, 72, 7N input to the respective data processing units 201 to 20N are separated into a reception baseband signal and a reception control signal. The received baseband signal is output to a baseband signal processing unit (not shown). The reception control signal processes various setting responses and monitoring responses of the wireless transmission / reception units 101 to 10N.
[0068]
FIG. 7 is a diagram showing a time chart of the delay time measurement of the delay measurement unit.
[0069]
Further, the delay measuring unit 7 that has received the spread timing signal 81 from the spread unit 2 and the despread timing signal 82 from the despread unit 6 transmits the first and second wireless transmit and receive units 101 to 10N as shown in FIG. The transmission / reception optical fiber delay can be calculated from the difference between the head of the second spreading code (the head of the 1 ms cycle) and the head of the second spreading code (the head of the 1 ms cycle) received from each of the wireless transmission / reception units 101 to 10N, By setting the transmission / reception optical fiber delay to １／, the delay time between the wireless base station device 1 and each of the wireless transmission / reception units 101 to 10N can be calculated. The accuracy of the delay time at this time is based on the diffusion unit shown in FIG. 6, and in this case, an accuracy of 1 / 14.8 MHz (about 3/100 chip) can be obtained.
[0070]
Also, when it is desired to measure the delay time during operation, there is no need to insert data for delay time measurement into the control signal and the baseband signal, so that the measurement can be performed while the system is normally operated.
[0071]
FIG. 8 is a diagram showing another example when the transmission format is spread.
[0072]
As another embodiment of the present invention, as shown in FIG. 8, when eight radio transmitting / receiving units are connected and spread every eight bits, an accuracy of 1 / 24.96 MHz (about 4/1000 chips) is obtained. Can be obtained.
[0073]
As described above, in a wireless base station system in which a plurality of transmitting and receiving antennas are distant, a transmission signal between the wireless base station device and the transmitting and receiving antennas is converted into a digital signal, and the transmitting side multiplexes the digital signals of the plurality of transmitting and receiving antennas by CDMA. By separating the digital signals of a plurality of transmitting and receiving antennas on the receiving side, the delay time between the radio base station apparatus and the transmitting and receiving antennas can be measured with high accuracy without stopping existing services.
[0074]
【The invention's effect】
As described above, the radio base station system of the present invention can measure the delay time between the radio base station device and the transmitting / receiving antenna with high accuracy, and can measure the delay time during operation. This has the effect of providing a wireless base station system capable of measuring delay time without stopping service even when the amount changes.
[Brief description of the drawings]
FIG. 1 is a block diagram showing one embodiment of a wireless base station system of the present invention.
FIG. 2 is a detailed block diagram illustrating an example of the wireless base station device of FIG.
FIG. 3 is a detailed block diagram illustrating an example of a wireless transmission / reception unit of FIG. 1;
FIG. 4 is a diagram illustrating an example of a multiplexing method of a baseband signal and a transmission control signal.
FIG. 5 is a diagram illustrating an example of a spreading code used in a spreading unit and a despreading unit.
FIG. 6 is a diagram illustrating an example of a case where a transmission format is spread.
FIG. 7 is a diagram showing a time chart of delay time measurement of a delay measuring unit.
FIG. 8 is a diagram showing another example when a transmission format is spread.
FIG. 9 is a diagram showing a transmission format in a conventional time division method.
[Explanation of symbols]
1 wireless base station device
2 Diffusion unit
3 Multiplex section
4 Electric / optical converter
5 Optical / electrical conversion unit
6 Despreading part
7 Delay measurement section
8 Optical / electrical conversion unit
9 Separation unit
10 Electric / optical converter
11 Reverse diffusion unit
12 Transmission wireless processing unit
13 Circulator section
14 Antenna part
15 Reception wireless processing unit
16 Diffusion unit
17 Light / Electric Converter
18 Multiplex part
19 Electric / optical converter
21, 22, 2N transmission composite signal
31, 32, 3N transmission composite signal
41 Transmission multiplex signal
42 Transmission multiplexed signal
43 Receive multiplexed signal
44 Receive multiplex signal
45, 46, 47 transmission multiplex signal
48 Transmission composite signal
49 Despread timing signal
51 Transmission radio signal
52 received radio signal
53, 54 Received composite signal
55, 56 Receive multiplexed signal
71, 72, 7N Received composite signal
81 Spread timing signal
82 despreading timing signal
101, 102, 10N wireless transceiver
201, 202, 20N Data processing unit

Claims

A radio base station system in which a plurality of radio base station devices and a plurality of transmission / reception antennas are distant, wherein a transmission signal between the radio base station device and the transmission / reception antenna is a digital signal, and a digital signal of the plurality of transmission / reception antennas on a transmission side. Are multiplexed by a CDMA (Code Division Multiple Access) method, and the receiving side separates digital signals of the plurality of transmitting and receiving antennas, thereby measuring a delay time between the radio base station apparatus and the transmitting and receiving antennas. Wireless base station system.

A wireless base station device, comprising a plurality of remote cascade-connected wireless transmitting and receiving units for communication connection with the wireless base station device;
The wireless base station device,
A plurality of first transmission combined signals are respectively output to the plurality of distant wireless transmission / reception units, and a plurality of reception combined signals from the plurality of distant wireless transmission / reception units are input, and each performs data processing. A plurality of data processing units;
A spreading unit that receives the plurality of first transmission combined signals from the plurality of data processing units, performs spreading processing, and outputs a plurality of second transmission combined signals;
A multiplexing unit that inputs the plurality of second transmission combined signals output from the spreading unit, multiplexes the second combined transmission signals, and outputs a transmission multiplexed signal;
An electrical / optical converter that converts an electrical signal of the transmission multiplex signal output from the multiplexing unit into an optical signal and outputs the optical signal as a transmission multiplexed signal to the wireless transmission / reception unit;
An optical / electrical conversion unit that receives a reception multiplexed signal from the wireless transmission / reception unit, converts the optical signal into an electric signal, and outputs the electric signal as a reception multiplexed signal;
A despreading unit that inputs and despreads the received multiplexed signal output from the optical / electrical conversion unit and separates and outputs the plurality of received combined signals;
Delay measurement for receiving a spread timing signal of the plurality of second transmission combined signals from the spreading unit and a despread timing signal of the plurality of reception combined signals from the despreading unit and measuring a delay time of a transmission / reception signal Department and;
A radio base station system comprising:

A wireless base station device, comprising a plurality of remote cascade-connected wireless transmitting and receiving units for communication connection with the wireless base station device;
The wireless transmitting and receiving unit,
A first optical / electrical conversion unit that receives a transmission multiplexed signal output from the wireless base station apparatus and converts an optical signal into an electric signal;
A separation unit that receives the transmission multiplex signal output by the first optical / electrical conversion unit, divides the transmission multiplex signal into two, and outputs a first transmission multiplex signal and a second transmission multiplex signal;
A first electrical / optical converter that converts the electrical signal of the first transmission multiplex signal output by the demultiplexer into an optical signal and outputs the optical signal to the wireless transceiver;
A despreading unit that receives the second transmission multiplexed signal output by the demultiplexing unit, extracts and outputs a required transmission combined signal by despreading, and outputs a despreading timing signal;
A transmission radio for receiving the transmission composite signal output by the despreading unit, separating a transmission baseband signal and a control signal, performing digital / analog conversion and frequency conversion on the transmission baseband signal, and outputting the converted signal as a transmission radio signal. Processing unit;
A circulator section for inputting and outputting the transmission radio signal output from the transmission radio processing section;
An antenna unit for transmitting a radio signal output from the circulator unit to the outside and receiving a radio signal from the outside;
By generating a reception baseband signal obtained by performing frequency conversion and analog-to-digital conversion on the reception radio signal from the antenna unit and the circulator unit, and synthesizing the reception baseband signal and the control signal, a first reception synthesis signal is obtained. A receiving wireless processing unit for outputting;
A spreading unit that receives the first received combined signal output from the receiving wireless processing unit and the despread timing signal output from the despreading unit, performs spreading processing, and outputs a second received combined signal;
A second optical / electrical conversion unit that converts an optical signal from the wireless transmission / reception unit into an electric signal and outputs the electric signal as a first reception multiplexed signal;
A multiplexing unit that multiplexes the second received combined signal output by the spreading unit and the first received multiplexed signal output by the second optical / electrical converter, and outputs the multiplexed signal as a second received multiplexed signal When;
A second electrical / optical converter that converts the electrical signal of the second multiplexed signal output by the multiplexer into an optical signal and outputs the optical signal to the wireless base station apparatus;
A radio base station system comprising:

The optical serial transmission using an optical fiber suitable for long-distance transmission is performed between the wireless base station device and the wireless transmitting / receiving unit and between the wireless transmitting / receiving unit and another wireless transmitting / receiving unit. The wireless base station system according to claim 2 or claim 3.

5. The wireless base station system according to claim 4, wherein the wireless base station apparatus has eight wireless transceiver units connected by one optical fiber for transmission and reception.

Each of the plurality of data processing units included in the wireless base station apparatus, the plurality of first transmission composite signals obtained by time division multiplexing a transmission baseband signal and a transmission control signal output to the wireless transmission / reception unit, 3. The radio base station system according to claim 2, wherein the signal is output to a spreading unit.

The eight second transmission combined signals input to the multiplexing unit of the wireless base station device are multiplexed without changing a transmission rate by code multiplexing using a CDMA (Code Division Multiple Access) method. 3. The radio base station system according to claim 2, wherein the transmission multiplexed signal is output to the electrical / optical converter.

The transmission multiplex signal input to the electric / optical conversion unit of the wireless base station device is obtained by converting parallel data into serial data, then converting from electricity to an optical signal, and converting the transmission multiplex signal into an optical signal. The radio base station system according to claim 2, wherein the converted signal is output to the radio transmission / reception unit via an optical fiber.

The delay measurement unit included in the wireless base station device,
The spreading timing signal from the spreading unit and the despreading timing signal from the despreading unit are input, and the head of the spreading code transmitted to each of the plurality of wireless transmitting and receiving units, and each of the plurality of wireless transmitting and receiving units 3. The transmission / reception optical fiber delay is calculated from a difference from the head of the spread code received from the mobile station, and delay times of the radio base station apparatus and the plurality of radio transmission / reception units are calculated. Wireless base station system.

7. A wireless base station system, wherein transmission data processed by the wireless base station system according to claim 2 is multiplexed by a CDMA system.