JP3604526B2

JP3604526B2 - Wireless communication space

Info

Publication number: JP3604526B2
Application number: JP04313597A
Authority: JP
Inventors: 康博岸野; 一浩上原; 憲一鹿子嶋
Original assignee: Nippon Telegraph and Telephone Corp; NTT Inc USA
Current assignee: NTT Inc; NTT Inc USA
Priority date: 1997-02-27
Filing date: 1997-02-27
Publication date: 2004-12-22
Anticipated expiration: 2017-02-27
Also published as: JPH10242683A

Description

【０００１】
【発明の属する技術分野】
本発明は屋内高速無線通信に関し、壁、床、天井からの反射によるマルチパスフェージングを軽減し、誤り率（ＢＥＲ）、Ｄ／Ｕ（希望波と干渉波の比）を改善した高品質な伝送を可能とする屋内高速無線通信の実現に係る。
【０００２】
【従来の技術】
図８は、従来の屋内高速無線通信装置と短遅延の干渉波の伝搬経路を示す図である。同図において、数字符号１は床、２は基地局アンテナ背後の壁、３は端局アンテナの背後の壁、４は天井、５は基地局装置、６は端末装置、７は基地局アンテナ、８は端局アンテナ、９は基地局アンテナの垂直面内における放射パターンを表わしている。
【０００３】
また、１０は端局アンテナの垂直面内における放射パターン、１４は基地局アンテナから直接、端末アンテナに到来する波の伝搬経路、１５は基地局アンテナより放射し、床に反射した後、端末アンテナに到来する波の伝搬経路、１６は基地局アンテナより放射し、天井で反射した後、端末アンテナに到来する波の伝搬経路を表わしている。
【０００４】
基地局アンテナ７は天井高と同程度、またはそれより低い高さに設置され、部屋の端に設置された端末局アンテナ８と通信を行う。基地局アンテナの垂直面内放射パターンは、基地局アンテナの垂直面内における放射パターンのピークが端末局アンテナの方向と一致するように水平方向から下方に傾けられている。
【０００５】
基地局アンテナから端末局アンテナヘ到来する波としては、基地局アンテナから放射された後、直接、端末局アンテナに到来する直接波以外に、基地局アンテナより放射され、床に反射した後、端末局アンテナに到来する波、及び基地局アンテナより放射され、天井で反射した後、端末局アンテナに到来する波がある。これらの波は基地局アンテナから直接端末局アンテナに到来する波の伝搬時間との差（これを遅延時間と呼ぶ）が短い、いわゆる短遅延の干渉波である。
【０００６】
図９は従来の屋内高速無線通信装置と長遅延の干渉波の伝搬経路を示す図である。同図において、数字符号１〜１０は図８と共通に用いている。基地局アンテナからの放射指向性は、対向する端末局アンテナのみならず端末局アンテナ背後の壁や天井にも向けられている。
【０００７】
このため、基地局アンテナから端末局アンテナヘ到来する波としては、数字符号１７で示す基地局アンテナから放射され、端末局アンテナ背後の壁で反射し、基地局アンテナ背後の壁で再び反射した後、端末局アンテナに到来する波、及び１８で示す基地局アンテナ近傍の天井に反射し、端末局アンテナ背後の壁で反射し、さらに基地局アンテナ背後の壁で再び反射した後、端末局アンテナに到来する波が存在する。
【０００８】
これらの波は、いわゆる長遅延の干渉波である。このため、屋内高速無線通信装置では、短遅延の干渉波である床や天井、側壁による１回反射波の干渉により受信レベルが低下した状態にさらに長遅延の干渉波である端末局アンテナ背後の壁と基地局アンテナ背後の壁でそれぞれ反射した２回以上反射した反射波とが干渉し、符号誤りを発生させ、伝送特性を劣化させている。
【０００９】
すなわち、伝送速度が数１０Ｍbit／ｓにも達する準ミリ波、ミリ波帯を使った屋内高速ディジタル伝送では、干渉波の遅延時間がシンボル長と同程度となり、干渉波の遅延時間がシンボル長の内外に存在する。このような屋内マルチパス環境下では、符号誤り率は干渉波の遅延時間には依存せず、希望波の受信レベル（Ｄ）と干渉波の全受信レベル（Ｕ）との比（Ｄ／Ｕ）により決定される。
【００１０】
（文献：中山，佐藤，吉田：“ミリ波による屋内高速伝送特性”，信学論（Ｂ），vol.77-C-I, no.11. pp.640-647, Nov.1994参照）
このため、「伝送速度が数１０Ｍbit／ｓにも達するミリ波帯での屋内高速ディジタル伝送では、多数の干渉波に対する所望波のＤ／Ｕを改善することが屋内高速通信の実現の基本といえる。」
【００１１】
このような、端末局アンテナと基地局アンテナの背後の壁でそれぞれ反射した２回以上反射した反射波の干渉による伝送特性の劣化を改善するためには、屋内の壁面で到来波を吸収し、対向する壁や天井からの反射波を全て抑圧するか、垂直面内放射パターンにおいて、基地局アンテナからみて対向する壁や天井を見込む角度にヌル点を形成することにより、対向する壁や天井からの反射波を全て抑圧すれば、干渉波に対するＤ／Ｕを改善できることは容易に考えられる。
【００１２】
従来、この条件を満足する部屋の一例として電波無響室が開示されている。一方この条件を満足する放射パターン形状のアンテナを実現するアンテナの一例として垂直面内の放射パターンがコセカント２乗の形状を持つ、いわゆるコセカント２乗成形ビームアンテナ等が開示されている。
【００１３】
図１０は従来の電波無響室の干渉波抑圧原埋を示す図である。同図において、（ａ）は電波無響室、（ｂ）は電波半無響室を示しており、数字符号１は床、２は基地局アンテナ背後の壁、３は端局アンテナの背後の壁、４は天井、５は基地局装置、６は端末装置、７は基地局アンテナ、８は端局アンテナ、９は基地局アンテナの垂直面内における放射パターン、１０は端局アンテナの垂直面内における放射パターン、２７は電波吸収面を示している。
【００１４】
この図において、実線で示した経路は実際の伝搬経路、破線は反射させない電波が反射した場合の伝搬経路を示している。
通常、基地局アンテナからの放射指向性は、対向する端末局アンテナのみならず端末局アンテナ背後の壁や天井にも向けられている。
【００１５】
このため、基地局アンテナから端末局アンテナヘ到来する波としては、１４の基地局アンテナから放射された後、直接、端末局アンテナに到来する直接波以外に、１５の基地局アンテナより放射され、床に反射した後、端末局アンテナに到来する波、及び１６の基地局アンテナより放射され、天井で反射した後、端末局アンテナに到来する波、
【００１６】
さらに１７の基地局アンテナから放射され、端末局アンテナ背後の壁で反射し、基地局アンテナ背後の壁で再び反射した後、端末局アンテナに到来する波、及び１８の基地局アンテナ近傍の天井に反射し、端末局アンテナ背後の壁で反射し、さらに基地局アンテナ背後の壁で再び反射した後、端末局アンテナに到来する波が本来なら存在する。
【００１７】
しかし、電波無響室では壁、天井、床の全ての面が電波吸収体で構成された電波吸収面であるため、数字符号１４で示す基地局アンテナから放射された後、直接、端末局アンテナに到来する直接波以外の基地局アンテナから放射された波は、壁、天井、床のいずれかに最初に到達した時点で電波吸収面に吸収されてしまい、壁、天井、床で反射する場合の通常の伝搬経路の破線で表示された区間は存在しなくなる。
【００１８】
すなわち、電波無響室では、壁、天井、床の全ての面で反射をさせないことにより、全ての干渉波を最初の壁面到達時に抑圧している。
特に、電波無響室で屋外環境を模して大地に相当する床面の反射を許容し、床以外の天井、壁面で反射させない図１０（ｂ）に示すものを電波半無響室と呼び、床面反射波に関しては２回目の反射点（床面反射後の最初の天井、壁面での反射点）、それ以外の反射波に関しては１回目の反射点で必ず電波を吸収することにより反射波を抑圧する。
【００１９】
【発明が解決しようとする課題】
しかし、上述したような電波無響室を実現するためには、壁面の全面工事が必要である。従って、工事の規模が非常に大きくなり、スペース的にも、経済的にも、通常の事務室や居室、教室等の部屋を電波無響室にするということは特別な場合を除いて現実的ではない。
【００２０】
また、成形ビームアンテナで所望の放射パターンを実現するためには、少なくとも数１０素子の素子アンテナが必要であることから、給電回路を含めたアンテナ装置全体が非常に大きくなる。
また、成形ビームアンテナでは素子間の励振振幅の比が大きくなることから、製造精度による誤差が無視できなくなり、特にミリ波帯では製造精度の影響が顕著になり、所望の性能を実現することが困難になるという問題がある。
【００２１】
以上述べたように、電波無響室では工事規模が非常に大きく、電波無響室を通常の部屋として使用することは経済的に難しい。また、従来の屋内無線通信装置の対応では、基地局アンテナとして成形ビームアンテナを用いていたため、アレーを構成する素子数が多くなり、アンテナ装置全体が大きくなり、これに加え、アンテナ装置の製作及び所望の性能の実現が困難になるという問題があった。
【００２２】
本発明の屋内高速無線通信に関する上述のような課題に対し、受信アンテナ背後の壁や天井からの１〜２回以上の反射波を抑圧して、長遅延反射波によるマルチパスフェージングを低減させ、希望波の受信レベル（Ｄ）と干渉波の全受信レベル（Ｕ）との比（Ｄ／Ｕ）を大きく改善することにより、高品質な屋内無線通信を簡易なアンテナ構成の無線通信装置で実現することを目的としている。
【００２３】
【課題を解決するための手段】
本発明によれば、上述の課題は、前記特許請求の範囲に記載した手段により解決される。
【００２４】
すなわち、本願の請求項に係る発明の基本的な構成は、対向する２つの壁面に挟まれた屋内等の空間内で、少なくとも１つの基地局と少なくとも１つの端末局の間で無線通信を行う系において、基地局アンテナから端末局アンテナヘ到来する１回以上壁面反射した長遅延波を端末局アンテナ到来前の伝搬経路途中のいずれかの反射点において反射を抑圧する長遅延波の伝搬遮断法を用い、
【００２５】
長遅延波遮断に要する反射を抑圧する範囲を最小共通となる特定範囲に制限し、その範囲の壁面を、電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、電波を吸収する材質もしくは反射係数の小さな材質の部材で覆うことにより構成した無線通信空間である。具体的な構成を以下に示す。
【００２６】
請求項１の発明は、平行に対向する２つの壁面に挟まれた空間内で、少なくとも１つの基地局と少なくとも１つの端末局の間で無線通信を行う系において、基地局アンテナが壁Ｂの壁面に設置され、壁Ａと壁Ｂで構成される対向壁間の距離をＬとしたとき、床から端末局アンテナまでの高さをＨｒ、床から基地局アンテナまでの高さをＨｔとするとき、
【００２７】
Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる床からの高さが、 “表５”の項番１〜５のいずれか１項で表わされる、壁Ａと壁Ｂの壁面上の範囲を、電波を吸収する材質、もしくは、反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆うことにより構成した無線通信空間である。
【００２８】
【表５】

【００２９】
請求項２の発明は、平行に対向する２つの壁面に挟まれた空間内で、少なくとも１つの基地局と少なくとも１つの端末局の間で無線通信を行う系において、壁Ａと壁Ｂで構成される対向壁間の距離すなわち部屋の長さをＬ、ａを１以上の実数としたとき、基地局アンテナと部屋の対向壁（壁Ａ）面までの距離をＬ／ａ、床から端末局アンテナまでの高さをＨｒ、床から基地局アンテナまでの高さをＨｔとするとき、
【００３０】
Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる、床からの高さが、ａの値が、５／４≦ａ≦５の場合 “表６”の項番１、１＜ａ＜５／４の場合、“表６”の項番２〜４、５＜ａの場合、“表６”の項番５〜７のいずれか１項で表わされる、壁Ａと壁Ｂの壁面上の範囲を電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆うことにより構成した無線通信空間である。
【表６】

【００３１】
請求項３の発明は、平行に対向する２つの壁面に挟まれた空間内で、少なくとも１つの基地局と少なくとも１つの端末局の間で無線通信を行う無線通信空間において、壁面反射等によるマルチパス干渉に関する天井反射の影響が大きい場合に、基地局アンテナが壁Ｂの壁面に設置され、壁Ａと壁Ｂで構成される対向壁間の距離をＬとしたとき、天井の高さをｈ、床から端末局アンテナまでの高さをＨｒ、床から基地局アンテナまでの高さをＨｔとするとき、
【００３２】
前記請求項１で示した床からの高さの範囲の壁面に加え、Ｈ＝２ｈ−Ｈｔ−Ｈｒで与えられる天井反射の鏡像送受信高低差のＨを使用して求められる床からの高さの範囲が“表７”の項番１〜５のいずれかで表わされる、壁Ａと壁Ｂの壁面の範囲を電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆うことにより構成した無線通信空間である。
【表７】

【００３３】
請求項４の発明は、平行に対向する２つの壁面に挟まれた空間内で、少なくとも１つの基地局と少なくとも１つの端末局の間で無線通信を行う無線通信空間において、壁面反射等によるマルチパス干渉に関する天井反射の影響が大きい場合に、壁Ａと壁Ｂで構成される対向壁間の距離すなわち部屋の長さをＬ、ａを１以上の実数、基地局アンテナと部屋の対向壁（壁Ａ）面までの距離をＬ／ａ、天井の高さをｈ、床から端末局アンテナまでの高さをＨｒ、床から基地局アンテナまでの高さをＨｔとするとき、
【００３４】
前記請求項２で示した床からの高さの範囲の壁面に加え、Ｈ＝２ｈ−Ｈｔ−Ｈｒで与えられる天井反射の鏡像送受信高低差のＨを使用して求められる床からの高さの範囲が、ａの値が、５／４≦ａ≦５の場合、“表８”の項番１、１＜ａ＜５／４の場合、“表８”の項番２〜４、５＜ａの場合、“表８”の項番５〜７のいずれか１項で表わされる、壁Ａと壁Ｂの壁面上の範囲を電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆うことにより構成した無線通信空間である。
【表８】

【００３５】
請求項５の発明は、請求項１〜請求項５記載の無線通信空間において、電波を吸収する材質又は、反射係数の小さな材質により構成する範囲に該当する壁面にシールドガラス等の電波を反射する窓が含まれる場合、電波を吸収する材質又は、反射係数の小さな材質により構成する範囲に該当する範囲を電波を透過して反射係数の小さい材質のガラス等で構成するか、又は、電波を吸収する反射係数の小さな材質で構成したパネル、壁紙又は塗料で覆うことにより構成したものである。
【００３６】
請求項６の発明は、請求項１〜請求項５記載の無線通信空間において、電波を吸収する材質もしくは反射係数の小さな材質により構成する範囲に該当する壁面を電波を吸収する反射係数の小さな材質、又は、反射係数の小さな材質で構成したカーテン、ブラインド等の遮蔽幕で覆う構造としたものである。
【００３７】
請求項７の発明は、請求項１〜請求項５記載の無線通信空間において、電波を吸収する材質もしくは反射係数の小さな材質により構成する範囲に該当する壁面を電波を吸収する反射係数の小さな材質もしくは反射係数の小さな材質で構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆われた書庫、フェンス、パーティション等の什器で覆う構造としたものである。
【００３８】
本発明は、上述のように、平行に対向する２つの壁面に挟まれた屋内等の空間内で、少なくとも１つの基地局と少なくとも１つの端末局の間で無線通信を行う系において、通信の障害となる基地局アンテナから端末局アンテナへ到来する１回以上壁面反射した長遅延波を最初の反射点で反射を抑圧し、
【００３９】
長遅延波の端末局アンテナへの伝搬を遮断する代わりに、端末局アンテナ到来前の伝搬経路途中のいずれかの反射点において反射を抑圧する長遅延波の伝搬遮断法を用い、長遅延波遮断に要する反射を抑圧する範囲を最小共通となる特定範囲に制限する。
【００４０】
さらに部屋の壁面が平行であるという幾何学的特徴を利用することで、端末局アンテナ到来時に垂直面内での反射回数が多い伝搬経路ほど基地局アンテナからの放射角の幅が狭くなるので、反射回数の多い伝搬経路ほど伝搬途中の壁面上の反射点の範囲は狭く、大部分は伝搬途中の壁面上の反射点で、範囲が広い反射回数の少ない伝搬経路の壁面上の反射点の範囲に含まれる反射点が存在するという特徴を利用し、
【００４１】
問題となる全ての長遅延波の伝搬経路上の反射点を少なくとも１回含む壁面の範囲を最小限に特定し、その範囲の壁面を電波を吸収する材質又は、反射係数の小さな材質により構成することにより、無線通信装置自体を改良することなく、抑圧すべき長遅延波の端末局アンテナへの伝搬を断ち、長遅延反射波によるマルチパスフェージングを低減させ、希望波の受信レベル（Ｄ）と干渉波の受信レベル（Ｕ）との比（Ｄ／Ｕ）を大きく改善して、高品質な無線通信を行うことを可能とする。
【００４２】
従来技術では、抑圧すべき長遅延波の伝搬経路を考慮していなかったために、前記、従来の技術の項で説明した電波無響室や電波半無響室のように、長遅延波を抑圧する手段として全ての反射波を１回目もしくは２回目の壁面反射時に抑圧していた。このため、長遅延波を抑圧するために必要な電波を反射しない壁面の面積が非常に広くなるという問題があった。
【００４３】
電波無響室や電波半無響室のように、全ての壁面反射を防止し、必ず１回目もしくは２回目の反射点で電波を吸収するのではなく、基地局アンテナから端末局アンテナへ到来する１回以上壁面反射した抑圧すべき長遅延波は端末局アンテナ到来前の伝搬経路上のいずれかの反射点において反射させなければ抑圧できる。
【００４４】
この原理を利用することにより電波を反射しない壁面の範囲を限定し、その面積を非常に小さくしても、長遅延波を抑圧し、Ｄ／Ｕを改善することが可能となる。この点が本発明の従来技術と異なる点である。
【００４５】
【発明の実施の形態】
以下、本発明の実施の形態に関し、図に基づいて、実施例として詳細に説明する。
図１は本発明の第１の実施例を示す図である。同図において、数字符号１は床、２は基地局アンテナ背後の壁（壁Ｂ）、３は端末局アンテナ背後の壁（壁Ａ）、４は天井、５は基地局装置、６は端末局装置、７は基地局アンテナ、８は端末局アンテナ、９は基地局アンテナの垂直面内における放射パターンを表わしている。
【００４６】
また、１０は端末局アンテナの垂直面内における放射パターン、１２は電波を吸収する材質又は、反射係数の小さな材質で構成される壁面部分、１３は電波を吸収する材質又は、反射係数の小さな材質で構成される壁面部分、１４は基地局アンテナから直接、端末局アンテナに到来する波の伝搬経路を表わしている。
【００４７】
さらに、１７は基地局アンテナより、端末局アンテナ背後の壁３に反射し、基地局アンテナ背後の壁２に反射した後、端末局アンテナに到来する波（破線区間は反射させない範囲で反射させた場合の伝搬経路）、１８は基地局アンテナより天井４で反射し、端末局アンテナ背後の壁３に反射し、さらに基地局アンテナ背後の壁２に反射した後、端末局アンテナに到来する波（破線区間は反射させない範囲で反射させた場合の伝搬経路）を表わしている。
【００４８】
本発明の実際の電波の伝搬には、壁面部分１２，１３では反射しないため伝搬経路１７及び１８の破線区間の伝搬はない。
図２は本発明の対向する壁と基地局アンテナの配置を説明する図である。
図２（ａ）は床に対して垂直な壁Ａと壁Ｂの間隔をＬ、天井の高さをｈ、床から基地局アンテナまでの高さをＨｔ、床から端末局アンテナまでの高さをＨｒとした、基地局アンテナが壁Ｂの壁際に設置される場合の垂直断面図である。
【００４９】
図２（ｂ）は床に対して垂直な壁Ａと壁Ｂの間隔をＬ、天井の高さをｈ、床から基地局アンテナまでの高さをＨｔ、床から端末局アンテナまでの高さをＨｒ、基地局アンテナと部屋の対向壁（壁Ａ）面までの距離をＬ／ａ（但し、１≦ａ＜∞）とした、基地局アンテナが壁間に配置される場合の垂直断面図である。
【００５０】
図３は本発明の高低差Ｈの値と送信高Ｔを説明する図である。
図３（ａ）は通常の送受信高低差のＨと送信高Ｔを表わす垂直断面図である。壁Ａと壁Ｂで構成される対向壁間の距離を部屋の長さＬ、基地局アンテナと部屋の対向壁（壁Ａ）面までの距離をＬ／ａ（但し、１≦ａ＜∞）、床から端末局アンテナまでの高さをＨｒ、床から基地局アンテナまでの高さをＨｔとするとき、
【００５１】
Ｈ＝Ｈｔ−Ｈｒ（送受信高低差の式）
として容易に求めることができる。
送信高Ｔは送信点の高さＨｔと等しく
Ｔ＝Ｈｔ＝Ｈ＋Ｈｒ
として求めることができる。
【００５２】
図３（ｂ）は天井反射による鏡像送受信高低差のＨと送信高Ｔを表わす垂直断面図である。
壁Ａと壁Ｂで構成される対向壁間の距離を部屋の長さをＬ、基地局アンテナと部屋の対向壁（壁Ａ）面までの距離をＬ／ａ（但し、１≦ａ＜∞）、床から端末局アンテナまでの高さをＨｒ、床から基地局アンテナまでの高さをＨｔとするとき、
【００５３】
Ｈ＝２ｈ−Ｈｔ−Ｈｒ（天井反射の鏡像送受信高低差の式）
と容易に求めることができる。
送信高Ｔは鏡像送信点の場合を考慮すると
Ｔ＝Ｈ＋Ｈｒ
として求めることができる。
【００５４】
図４は本発明の基地局アンテナと壁の位置関係を示す平面図である。
部屋の幅（壁Ｂ′−壁Ａ′）方向をＸ軸方向とし部屋の幅をＬｘとする。部屋の奥行き（壁Ｂ″−壁Ａ″）方向をＹ軸方向、部屋の奥行きをＬｙとする。基地局アンテナと部屋の壁Ａ′面までの距離はＬｘ／ｂ（１≦ｂ＜∞）、基地局アンテナと部屋の壁Ａ″面までの距離はＬｙ／ｃ（１≦ｃ＜∞）と表わすことができる。
【００５５】
図５は本発明の対向する壁と基地局アンテナの位置関係を説明する垂直面図である。
通常、部分的に考えた屋内の形状は直方体と考えられるため、屋内を直交座標（ＸＹＺ座標）として考え、部屋の幅方向をＸ方向、部屋の奥行き方向をＹ方向、垂直方をＺ方向とすると、電波伝搬の垂直方向（Ｚ軸方向）変化はＸ−Ｚ座標成分とＹ−Ｚ座標成分に分解できる。
【００５６】
図５（ａ）は図４のｘ軸方向の垂直断面図であり、
図５（ｂ）は図４のＹ軸方向の垂直断面図である。
図４における、Ｘ軸方向断面とＹ軸方向断面を一般化して壁を壁Ａ、壁Ｂとし、壁Ａ、壁Ｂ間の距離をＬ、基地局アンテナと部屋の壁Ａ面までの距離はＬ／ａ（但し１≦ａ＜∞）と表わすことができる。
【００５７】
図６は本発明の第１の実施例の電波を反射させない壁面の範囲の定式化を説明する図である。
Ｔは送信高、Ｌは床に対して垂直な壁Ａと壁Ｂの間隔、Ｈは鏡像送受信高低差、Ｈｒは床から端末局アンテナまでの高さとして、基地局アンテナが壁Ｂの壁際に設置される場合の同一垂直断面図を７つ連結させて示した図である。送信高Ｔは鏡像送信点の場合を考慮すると
Ｔ＝Ｈ＋Ｈｒ
として容易にもとめることができる。
【００５８】
長遅延波となる反射波で問題となるのは端末局アンテナへの到来方向が直接波と同じ方向（壁Ｂ→壁Ａ方向）になる、最後に基地局アンテナ背後の壁（壁Ｂ）に反射した後、端末局アンテナに到来する、壁Ａ〜壁Ｂで偶数回反射した反射波である。
【００５９】
基地局アンテナから放射され、端末局アンテナ背後の壁（壁Ａ）に反射し、基地局アンテナ背後の壁（壁Ｂ）に反射した後、端末局アンテナに到来する２回反射波の受信点は、送信点からの水平距離の範囲が２Ｌ〜３Ｌとなり、送信点と壁Ｂの受信点、壁Ａの受信点を結ぶ線はＬ間隔で平行な壁Ｂ、壁Ａに対して高低差Ｈを２等分、３等分した点と交わるため、２回反射波の反射点となる壁面の範囲は壁Ａでは高低差Ｈの１／２〜２／３、壁Ｂでは高低差Ｈの０〜１／３の範囲になる。
【００６０】
同様に４回反射波の受信点は、送信点からの水平距離の範囲が４Ｌ〜５Ｌとなるので、送信点と壁Ｂの受信点、壁Ａの受信点を結ぶ線は壁Ｂ、壁Ａに対して高低差Ｈを４等分、５等分した点と交わり、６回反射波の受信点は、送信点からの水平距離の範囲が６Ｌ〜７Ｌとなるので、送信点と壁Ｂの受信点、壁Ａの受信点を結ぶ線は壁Ｂ、壁Ａに対して高低差Ｈを６等分、７等分した点と交わる。
【００６１】
従って、２ｎ回反射波の受信点は送信点からの水平距離の範囲が２ｎＬ〜（２ｎ＋１）Ｌとなるので、送信点と壁Ａの受信点、壁Ｂの受信点を結ぶ線は壁Ｂ、壁Ａに対してそれぞれ高低差Ｈを２ｎ等分、（２ｎ＋１）等分した点と交わり、２ｎ回反射波のｍ回目の壁Ａでの反射点の範囲は
【００６２】
（２（ｎ−ｍ）＋１）Ｈ／２ｎ〜２（ｎ−ｍ＋１）Ｈ／（２ｎ＋１）
（但し、ｍはｎ以下の自然数）
と求めることができ、
２ｎ回反射波のｍ回目の壁Ｂでの反射点の範囲は
（ｎ−ｍ）Ｈ／ｎ〜（２（ｎ−ｍ）＋１）Ｈ／（２ｎ＋１）
（但し、ｍはｎ以下の自然数）
と求めることができる。
【００６３】
上記で求めた、２ｎ回反射波の壁Ａ及び壁Ｂでの反射点の範囲から伝搬経路上の壁面反射点で２ｎ回反射波を抑圧するために必要な範囲は以下のように場合分けできる。なお、上記の表５〜８の表をまとめた表を表９に示す。
【表９】
（但し、ａは１以上の実数とする。）

【００６４】
（１）壁Ａ壁面と壁Ｂ壁面の両方の反射点で抑圧する場合
（伝搬経路の中間反射点で抑圧）
（壁Ａ壁面上の２回反射波の最初の反射点、壁Ｂ壁面上の４回反射波の最初の反射点）
（イ）壁Ａ壁面と壁Ｂ壁面の均等な範囲（前記“表９”の項番１が相当する）
（ロ）壁Ａ壁面上の全ての４ｎ−２回反射波の中間点を、壁Ｂ壁面上の全ての４ｎ回反射波の中間点をカバーする範囲（“表９”の項番２が相当する）
【００６５】
（２）壁Ａ壁面の反射点のみで抑圧する場合
（伝搬経路の前半の反射点で抑圧）
２回反射波と４回反射波の反射点を抑圧する連続な範囲
（ハ）壁Ａ壁面上の２回反射波と４回反射波の最初の反射点を含む連続な範囲（“表９”の項番３が相当する）
（ニ）壁Ａ壁面上の２回反射波の最初の反射点と４回反射波の２回目の反射点を含む連続な範囲（“表９”の項番４が相当する）
【００６６】
（３）壁Ｂ壁面の反射点のみで抑圧する場合
（伝搬経路の最後の反射点で抑圧）
（ホ）壁Ｂ壁面の２回反射波の最後の反射点の範囲（“表９”の項番５が相当する）
に分けられる。
【００６７】
図７は本発明の第２の実施例の電波を反射させない壁面の範囲の定式化を説明する図である。
同図において、Ｔは送信高、Ｌは床に対して垂直な壁Ａと壁Ｂの間隔、基地局アンテナと部屋の対向壁（壁Ａ）面までの距離をＬ／ａ、ｈは天井の高さ、Ｈｔは床から基地局アンテナまでの高さ、Ｈｒは床から端末局アンテナまでの高さを示しており、同図はこのような同一垂直断面を有する部屋を８つ連結させた図である。
【００６８】
図７において、部屋０が実像、部屋１〜６が鏡像、部屋−１が水平面の鏡像送信点の部屋である。破線は送信点及び各部屋の鏡像送信点の水平位置を示す線である。送信高Ｔは、鏡像送信点の場合を考慮すると
Ｔ＝Ｈ＋Ｈｒ
として容易にもとめることができる。
長遅延波となる反射波で問題となるのは端末局アンテナへの到来方向が直接波と同じ方向になる、壁Ａ〜壁Ｂで往復反射して端末局アンテナに到来する反射波である。
【００６９】
基地局アンテナが壁Ａと壁Ｂの間に設置されている場合は、最後に基地局アンテナ背後の壁（壁Ｂ）で反射した、偶数回反射だけでなく、最後に端末局アンテナ背後の壁（壁Ａ）で反射した、奇数回反射波も、基地局アンテナ位置から基地局アンテナ背後の壁（壁Ｂ）までの範囲では端末局アンテナへの到来方向が直接波と同じ方向になる。
送信アンテナから壁Ａ方向のみ放射した場合の伝搬を考えると奇数回反射波は部屋番号が奇数の場合のみに存在し、偶数回反射波は部屋番号が偶数の場合のみに存在する。
【００７０】
基地局アンテナから放射され、端末局アンテナ背後の壁（壁Ａ）に反射後、端末局アンテナに到来する、１回反射波の受信点は部屋１の鏡像送信点の水平位置を示す線上の受信点から壁Ｂの受信点までの範囲で、送信点からの水平距離の範囲が２Ｌ／ａ〜（ａ＋１）Ｌ／ａとなり、送信点と受信点の始まりと終わりの境界点を結ぶ線は、壁Ａに対して高低差Ｈを分割して交わるため、１回反射波の反射点となる壁面の範囲は壁Ａでは高低差Ｈの１／２〜ａ／（ａ＋１）の範囲になる。
【００７１】
３回反射波の受信点は部屋３の鏡像送信点の水平位置を示す線上の受信点から壁Ｂの受信点までの範囲で、送信点からの水平距離の範囲がＬ（２ａ＋２）／ａ〜３Ｌ（ａ＋１）／ａとなり、送信点と受信点の始まりと終わりの境界点を結ぶ線は、壁Ａに対して高低差Ｈを分割して交わるため、３回反射波の反射点となる壁面の範囲は壁Ａでの反射１回目では高低差Ｈの（２ａ＋１）／（２ａ＋２）〜３ａ／（３ａ＋１）、反射２回目では高低差Ｈの１／（２ａ＋２）〜ａ／（３ａ＋１）、壁Ｂでは高低差Ｈの１／２〜２ａ／（３ａ＋１）の範囲になる。
【００７２】
同様に、５回反射波の受信点は部屋５の鏡像送信点の水平位置を示す線上の受信点から壁Ｂの受信点までの範囲で水平距離の範囲がＬ（４ａ＋２）／ａ〜Ｌ（５ａ＋１）／ａとなる。
すなわち、送信点からの奇数ｎ回反射波の鏡像受信点の水平距離の範囲は
（（ｎ−１）ａ＋２）Ｌ／ａ〜（ｎａ＋１）Ｌ／ａ
（但し、ｎ＝２Ｑ−１でＱは自然数）となる。
【００７３】
従って、
奇数ｎ回反射波のｍ回目の壁Ａでの反射点の範囲は
（ａ（ｎ−２ｍ＋１）＋１）Ｈ／（（ｎ−１）ａ＋２）〜ａ（ｎ−２ｍ＋２）Ｈ／（ｎａ＋１）
（但し、ｍはＱ以下の自然数、ｎ＝２Ｑ−１でＱは自然数）と求めることができ、
【００７４】
奇数ｎ回反射波のｍ回目の壁Ｂでの反射点の範囲は
（ａ（ｎ−２ｍ）＋１）Ｈ／（（ｎ−１）ａ＋２）〜ａ（ｎ−２ｍ＋１）Ｈ／（ｎａ＋１）
（但し、ｍはＱ未満の自然数、ｎ＝２Ｑ−１でＱは自然数）と求めることができる。
【００７５】
次に、偶数回反射波について考える。
基地局アンテナから放射され、端末局アンテナ背後の壁（壁Ａ）に反射し、基地局アンテナ背後の壁（壁Ｂ）に反射した後、端末局アンテナに到来する、２回反射波の受信点は部屋２の鏡像送信点の水平位置を示す線上の受信点から壁Ａの受信点までの範囲で水平距離の範囲が２Ｌ〜（２ａ＋１）Ｌ／ａとなり、
【００７６】
送信点と受信点の始まりと終わりの境界点を結ぶ線は、壁Ａと壁Ｂに対して高低差Ｈを分割して交わるため、２回反射波の反射点となる壁面の範囲は壁Ａでは高低差Ｈの（２ａ−１）／２ａ〜２ａ／（２ａ＋１）、壁Ｂでは高低差Ｈの（ａ−１）／２ａ〜ａ／（２ａ＋１）の範囲になる。
【００７７】
４回反射波の受信点は部屋４の鏡像送信点の水平位置を示す線上の受信点から壁Ａの受信点までの範囲で水平距離の範囲が４Ｌ〜（４ａ＋１）Ｌ／ａとなり、送信点と受信点の始まりと終わりの境界点を結ぶ線は、壁Ａと壁Ｂに対して高低差Ｈを分割して交わるため、
【００７８】
４回反射波の反射点となる壁面の範囲は、壁Ａの反射１回目では、高低差Ｈの（４ａ−１）／４ａ〜４ａ／（４ａ＋１）、反射２回目では、高低差Ｈの（２ａ−１）／４ａ〜２ａ／（４ａ＋１）、壁Ｂの反射１回目では、高低差Ｈの（３ａ−１）／４ａ〜３ａ／（４ａ＋１）、反射２回目では、高低差Ｈの（ａ−１）／４ａ〜ａ／（４ａ＋１）の範囲になる。
【００７９】
同様に、６回反射波の受信点は部屋６の鏡像送信点の水平位置を示す線上の受信点から壁Ｂの受信点までの範囲で水平距離の範囲が６Ｌ〜（６ａ＋１）Ｌ／ａとなる。
すなわち、送信点からの偶数ｎ回反射波の鏡像受信点の水平距離の範囲は
ｎＬ〜（ｎａ＋１）Ｌ／ａ
（但し、ｎ＝２ＱでＱは自然数）
となる。
【００８０】
従って、
偶数ｎ回反射波のｍ回目の壁Ａでの反射点の範囲は
（ａ（ｎ−２ｍ）＋２）−１）Ｈ／ｎａ〜ａ（ｎ−２ｍ＋２）Ｈ／（ｎａ＋１）
（但し、ｍはＱ以下の自然数、ｎ＝２ＱでＱは自然数）
と求めることができる。
【００８１】
さらに、送信アンテナから壁Ｂ方向に放射した場合の伝搬を考慮するために、部屋番号−１の水平面の鏡像送信点から放射した場合には、奇数回反射波は部屋番号が偶数の場合のみに存在し、偶数回反射波は部屋番号が奇数の場合のみに存在する。
【００８２】
壁Ｂ方向に放射した場合の鏡像送信点からの奇数ｎ回反射波の鏡像受信点の水平距離の範囲は
（ｎａ＋ａ−２）Ｌ／ａ〜（ｎａ＋ａ−１）Ｌ／ａ
（但し、ｎ＝２Ｑ−１でＱは自然数）
となり、
鏡像送信点からの偶数ｎ回反射波の鏡像受信点の水平距離の範囲は
ｎＬ〜（ｎａ＋ａ−１）Ｌ／ａ
（但し、ｎ＝２ＱでＱは自然数）
となる。
【００８３】
従って、
壁Ｂ方向に放射した場合の奇数ｎ回反射波のｍ回目の壁Ａでの反射点の範囲は
（ａ（ｎ−２ｍ）＋１）−１）Ｈ／（ｎａ＋ａ−２）〜ａ（ｎ−２ｍ＋１）Ｈ／（ｎａ＋ａ−１）
（但し、ｍはＱ未満の自然数、ｎ＝２Ｑ−１でＱは自然数）と求めることができ、
【００８４】
壁Ｂ方向に放射した場合の奇数ｎ回反射波のｍ回目の壁Ｂでの反射点の範囲は
（ａ（ｎ−２ｍ＋２）−１）Ｈ／（ｎａ＋ａ−２）〜ａ（ｎ−２ｍ＋２）Ｈ／（ｎａ＋ａ−１）
（但し、ｍはＱ以下の自然数、ｎ＝２Ｑ−１でＱは自然数）と求めることができる。
【００８５】
次に、偶数回反射波について考える。
壁Ｂ方向に放射した場合の偶数ｎ回反射波のｍ回目の壁Ａでの反射点の範囲は
（ａ（ｎ−２ｍ）＋１）Ｈ／ｎａ〜（ｎ−２ｍ＋１）Ｈ／（ｎａ＋ａ−１）
（但し、ｍはＱ以下の自然数、ｎ＝２ＱでＱは自然数）と求めることができ、
【００８６】
壁Ｂ方向に放射した場合の偶数ｎ回反射波のｍ回目の壁Ｂでの反射点の範囲は
（ａ（ｎ−２ｍ＋１）＋１）Ｈ／ｎａ〜ａ（ｎ−２ｍ＋２）Ｈ／（ｎａ＋ａ−１）（但し、ｍはＱ以下の自然数、ｎ＝２ＱでＱは自然数）と求めることができる。
【００８７】
上記で求めた、壁Ａ、壁Ｂの送信点から壁Ａ方向、壁Ｂ方向へ放射した場合の壁Ａ及び壁Ｂでの反射点の範囲から伝搬経路上の壁面反射点で反射波を抑圧するために必要な範囲は以下のように場合分けできる。
【００８８】
（１）壁Ａからの送信アンテナ位置Ｌ／ａが５／４≦ａ≦５の場合
（壁Ａ壁面上の１〜２回反射波の最初の反射点と壁Ｂ壁面上の１〜２回反射波の最初の反射点の範囲）
（イ）送信アンテナ位置Ｌ／ａが５／４≦ａ≦５の場合
壁Ａ壁面側では、壁Ａで最初に反射して１〜２回反射波となる壁Ａ壁面上の最初の反射点を連続カバーし、壁Ｂ壁面側では、壁Ｂで最初に反射して１〜２回反射波となる壁Ｂ壁面上の最初の反射点を連続的にカバーする範囲（“表９”の項番１）
【００８９】
（２）壁Ａからの送信アンテナ位置Ｌ／ａが１＜ａ＜５／４の場合
（壁Ａで最初に反射する１〜２回反射波の反射点、壁Ｂで最初に反射する１〜４回反射波の反射点）
（ロ）壁Ａ壁面側では、壁Ａで最初に反射して１〜２回反射波となる壁Ａ壁面上の最初の反射点と壁Ｂで最初に反射して３〜４回反射波となる反射波の壁Ａ壁面上の最初の反射点を連続的にカバーする範囲を、壁Ｂ壁面側では、壁Ｂで最初に反射して１〜２回反射波となる壁Ｂ壁面上の最初の反射点を連続的にカバーする範囲（“表９”の項番７）
【００９０】
（ハ）壁Ａ壁面側では、壁Ａで最初に反射して１〜２回反射波となる壁Ａ壁面上の最初の反射点を連続的にカバーする範囲を、壁Ｂ壁面側では、壁Ｂで最初に反射して１〜４回反射波となる壁Ｂ壁面上の最初の反射点を連続的にカバーする範囲（“表９”の項番８）
（壁Ａで最初に反射する１〜２回反射波の反射点、壁Ｂで最初に反射する１〜２回反射波の反射点と４回反射波の２回目の反射点）
【００９１】
（ニ）壁Ａ壁面側では、壁Ａで最初に反射して１〜２回反射波となる壁Ａ壁面上の最初の反射点を連続的にカバーする範囲を、壁Ｂ壁面側では、壁Ｂで最初に反射して１〜２回反射波となる壁Ｂ壁面上の最初の反射点と壁Ｂで最初に反射して４回反射波となる反射波の壁Ｂ壁面上の２回目の反射点を連続的にカバーする範囲（“表９”の項番９）
【００９２】
（３）壁Ａからの送信アンテナ位置Ｌ／ａが５＜ａの場合
（壁Ａで最初に反射する１〜４回反射波の反射点、壁Ｂで最初に反射する１〜２回反射波の反射点）
（ホ）壁Ａ壁面側では、壁Ａで最初に反射して１〜２回反射波となる壁Ａ壁面上の最初の反射点を連続的にカバーする範囲を、壁Ｂ壁面側では、壁Ｂで最初に反射して１〜２回反射波となる壁Ｂ壁面上の最初の反射点と壁Ａで最初に反射して３〜４回反射波となる反射波の壁Ｂ壁面上の最初の反射点を連続的にカバーする範囲（“表９”の項番１０）
【００９３】
（ヘ）壁Ａ壁面側では、壁Ａで最初に反射して１〜４回反射波となる壁Ａ壁面上の最初の反射点を連続的にカバーする範囲を、壁Ｂ壁面側では、壁Ｂで最初に反射して１〜２回反射波となる壁Ｂ壁面上の最初の反射点を連続的にカバーする範囲（“表９”の項番１１）
（壁Ａで最初に反射する１〜２回反射波の反射点と４回反射波の２回目の反射点、壁Ｂで最初に反射する１〜２回反射波の反射点）
【００９４】
（ト）壁Ａ壁面側では、壁Ａで最初に反射して１〜２回反射波となる壁Ａ壁面上の最初の反射点と壁Ａで最初に反射して４回反射波となる反射波の壁Ａ壁面上の２回目の反射点を連続的にカバーする範囲を、壁Ｂ壁面側では、壁Ｂで最初に反射して１〜２回反射波となる壁Ｂ壁面上の最初の反射点を連続的にカバーする範囲（“表９”の項番１２）
【００９５】
図８は、従来の屋内高速無線通信装置と短遅延の干渉波の伝搬経路を示す図である。同図において、数字符号１は床、２は基地局アンテナ背後の壁、３は端局アンテナの背後の壁、４は天井、５は基地局装置、６は端末装置、７は基地局アンテナ、８は端局アンテナ、
【００９６】
９は基地局アンテナの垂直面内における放射パターン、１０は端局アンテナの垂直面内における放射パターン、１４は基地局アンテナから直接、端末アンテナに到来する波の伝搬経路、１５は基地局アンテナより放射し、床に反射した後、端末アンテナに到来する波の伝搬経路、１６は基地局アンテナより放射し、天井で反射した後、端末アンテナに到来する波の伝搬経路である。
【００９７】
図９は従来の屋内高速無線通信装置と長遅延の干渉波の伝搬経路を示す図である。同図において、数字符号１は床、２は基地局アンテナ背後の壁、３は端局アンテナの背後の壁、４は天井、５は基地局装置、６は端末装置、７は基地局アンテナ、８は端局アンテナ、９は基地局アンテナの垂直面内における放射パターン、１０は端局アンテナの垂直面内における放射パターンを表わしている。
【００９８】
また、１７は基地局アンテナより、端末局アンテナ背後の壁に反射し、基地局アンテナ背後の壁に反射した後、端末局アンテナに到来する波の伝搬経路、１８は基地局アンテナより天井で反射し、端末局アンテナ背後の壁に反射し、さらに基地局アンテナ背後の壁に反射した後、端末局アンテナに到来する波の伝搬経路である。
【００９９】
図１０は従来の電波無響室の干渉波抑圧原理を示す図である。数字符号１は床、２は基地局アンテナ背後の壁、３は端局アンテナの背後の壁、４は天井、５は基地局装置、６は端末装置、７は基地局アンテナ、８は端局アンテナ、９は基地局アンテナの垂直面内における放射パターン、
【０１００】
１０は端局アンテナの垂直面内における放射パターン、１４は基地局アンテナから直接、端末アンテナに到来する波の伝搬経路、１５は基地局アンテナより放射し、床に反射した後、端末アンテナに到来する波の伝搬経路、１６は基地局アンテナより放射し、天井で反射した後、端末アンテナに到来する波の伝搬経路、
【０１０１】
１７は基地局アンテナより、端末局アンテナ背後の壁に反射し、基地局アンテナ背後の壁に反射した後、端末局アンテナに到来する波の伝搬経路、１８は基地局アンテナより天井で反射し、端末局アンテナ背後の壁に反射し、さらに基地局アンテナ背後の壁に反射した後、端末局アンテナに到来する波の伝搬経路、２７は電波吸収面である。
【０１０２】
図１１は本発明の第１の実施例を示す図である。同図において、数字符号１は床、３は端局アンテナの背後の壁、４は天井、１２は壁Ａの壁面上の電波を吸収する材質又は、反射係数の小さな材質で構成される部分である。この例は本願発明の基本的な構成を示している。
【０１０３】
図１２は本発明の第２の実施例を示す図である。同図において、数字符号１は床、２は基地局アンテナ背後の壁（壁Ｂ）、３は端末局アンテナ背後の壁（壁Ａ）、４は天井、１２は壁Ａの壁面上の電波を吸収する材質又は、反射係数の小さな材質で構成される部分、１３は壁Ｂの壁面上の電波を吸収する材質又は、反射係数の小さな材質で構成される部分である。
【０１０４】
図１３は本発明の第３の実施例を示す図である。同図において、数字符号１は床、３は端局アンテナの背後の壁、４は天井、１９は、式Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる、電波を吸収する材質もしくは反射係数の小さな材質により構成するか、
【０１０５】
又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲、２０は、式Ｈ＝２ｈ−Ｈｔ−Ｈｒで与えられる天井反射の鏡像送受信高低差のＨを使用して求められる電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲である。
【０１０６】
図１４は本発明の第４の実施例を示す図である。同図において、数字符号１は床、２は基地局アンテナ背後の壁、３は端局アンテナの背後の壁、４は天井、１９は、式Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる、電波を吸収する材質もしくは反射係数の小さな材質により構成するか、
【０１０７】
又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲、２０は、式Ｈ＝２ｈ−Ｈｔ−Ｈｒで与えられる天井反射の鏡像送受信高低差のＨを使用して求められる電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲である。
【０１０８】
図１５は本発明の第５の実施例を示す図である。同図において、数字符号１は床、４は天井、１９は、式Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる、電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲である。
【０１０９】
図１６は本発明の第６実施例を示す図である。同図において、数字符号１は床、４は天井、１９は、式Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる、電波を吸収する材質もしくは反射係数の小さな材質により構成するか、
【０１１０】
又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲、２０は、式Ｈ＝２ｈ−Ｈｔ−Ｈｒで与えられる天井反射の鏡像送受信高低差のＨを使用して求められる電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲である。
【０１１１】
図１７は本発明の第７の実施例を示す図である。同図において、数字符号１９は、式Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる、電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲である。
【０１１２】
図１８は本発明の第８の実施例を示す図である。同図において、数字符号１９は、式Ｈ＝Ｈｔ−Ｈｒで与えられる送受信高低差のＨを使用して求められる、電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲、
【０１１３】
２０は、式Ｈ＝２ｈ−Ｈｔ−Ｈｒで与えられる天井反射の鏡像送受信高低差のＨを使用して求められる電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲である。
【０１１４】
図１９は本発明の第９の実施例を示す図である。同図において、数字符号１は床、４は天井、２１は電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲、２２は反射係数の小さい材質のガラス等で構成するか、又は、電波を吸収して反射係数の小さな材質で構成したパネル、壁紙又は塗料の壁面材で覆う窓の範囲、２３は窓、２４は壁である。
【０１１５】
図２０は本発明の第１０の実施例を示す図である。同図において、数字符号２１は電波を吸収する材質もしくは反射係数の小さな材質により構成するか、又は、前記の材質で構成したパネル、壁紙又は塗料で覆う壁面上の範囲、２４は壁、２５は書庫、パーティション等の什器、２６は什器の電波を吸収する材質、もしくは、反射係数の小さな材質で構成するか、又は、電波を吸収して反射係数の小さな材質で構成したパネル、壁紙又は塗料の壁而材で覆う什器の範囲である。
【０１１６】
【発明の効果】
以上、説明したように、本発明の無線通信空間は、無線ＬＡＮ等の屋内高速無線通信装置を実現する上で問題となるマルチパスフェージングを、壁面の特定な高さの帯状の範囲を電波の反射係数の小さな材質で構成するか、電波を吸収する材質の遮蔽物で覆うことによって、その原因となる放射角で伝搬する電波を伝搬経路上の反射点で反射波を反射させずに遮断することにより抑圧している。
【０１１７】
これによって、基地局アンテナにマルチパスフェージングを低減させるためのヌル点成形等の複雑なビーム成形機能持つアンテナを使用すること無く、対向する壁や天井からの１〜２回以上の反射波を抑圧できるので、長遅延反射波によるマルチパスフェージングを低減させて、誤り率（ＢＥＲ）、Ｄ／Ｕ（希望波と干渉波の比）を大きく改善した高品質な屋内高速無線通信を、非常に簡易なアンテナ構成の無線通信装置で実現することができる利点がある。
【図面の簡単な説明】
【図１】本発明の第１の実施例を説明する図である。
【図２】対向する壁と基地局アンテナの配置を説明する図である。
【図３】高低差Ｈの値と送信高Ｔを説明する図である。
【図４】基地局アンテナと壁の位置関係を示す平面図である。
【図５】対向する壁と基地局アンテナの位置関係を説明する垂直面図である。
【図６】第１の実施例の電波を反射させない壁面の範囲の定式化を説明する図である。
【図７】第２の実施例の電波を反射させない壁面の範囲の定式化を説明する図である。
【図８】従来の屋内無線通信装置と短遅延の干渉波の伝搬経路を示す図である。
【図９】従来の屋内無線通信装置と長遅延の干渉波の伝搬経路を示す図である。
【図１０】従来の電波無響室の干渉波抑圧原理を示す図である。
【図１１】本発明の第１の実施例を示す図である。
【図１２】本発明の第２の実施例を示す図である。
【図１３】本発明の第３の実施例を示す図である。
【図１４】本発明の第４の実施例を示す図である。
【図１５】本発明の第５の実施例を示す図である。
【図１６】本発明の第６の実施例を示す図である。
【図１７】本発明の第７の実施例を示す図である。
【図１８】本発明の第８の実施例を示す図である。
【図１９】本発明の第９の実施例を示す図である。
【図２０】本発明の第１０の実施例を示す図である。
【符号の説明】
１床
２基地局アンテナ背後の壁（壁Ｂ）
３端末局アンテナ背後の壁（壁Ａ）
４天井
５基地局装置
６端末局装置
７基地局アンテナ
８端末局アンテナ
９基地局アンテナの垂直面内の放射パターン
１０端末局アンテナの垂直面内の放射パターン
１１送信点（送信アンテナの位置）
１２，１３壁面上の電波を吸収する材質又は、反射係数の小さな材質で構成される部分
１４〜１８電波の伝搬経路
１９〜２１対策を施す壁面上の範囲
２２対策を施す窓上の範囲
２３窓
２４壁
２５書庫、パーティション等の什器
２６対策を施す什器上の範囲
２７電波吸収面[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to indoor high-speed wireless communication, and reduces multipath fading due to reflection from walls, floors, and ceilings, and achieves high-quality transmission with improved error rate (BER) and D / U (ratio of desired wave to interference wave). The present invention relates to the realization of indoor high-speed wireless communication that enables the communication.
[0002]
[Prior art]
FIG. 8 is a diagram illustrating a conventional indoor high-speed wireless communication device and a propagation path of a short-delay interference wave. In the figure, numeral 1 is a floor, 2 is a wall behind a base station antenna, 3 is a wall behind a terminal station antenna, 4 is a ceiling, 5 is a base station device, 6 is a terminal device, 7 is a base station antenna, Reference numeral 8 denotes a terminal station antenna, and 9 denotes a radiation pattern in a vertical plane of the base station antenna.
[0003]
10 is a radiation pattern in the vertical plane of the terminal antenna, 14 is a propagation path of a wave arriving at the terminal antenna directly from the base station antenna, 15 is radiated from the base station antenna and reflected on the floor. A propagation path 16 of the wave arriving at the base station antenna is radiated from the base station antenna and reflected by the ceiling, and thereafter, a propagation path of the wave arriving at the terminal antenna.
[0004]
The base station antenna 7 is installed at a height equal to or lower than the ceiling height, and communicates with the terminal station antenna 8 installed at the end of the room. The radiation pattern in the vertical plane of the base station antenna is inclined downward from the horizontal direction so that the peak of the radiation pattern in the vertical plane of the base station antenna coincides with the direction of the terminal station antenna.
[0005]
The waves arriving from the base station antenna to the terminal station antenna include, in addition to the direct waves arriving from the base station antenna and directly arriving at the terminal station antenna, the waves radiated from the base station antenna and reflected on the floor, There is a wave arriving at the antenna and a wave radiated from the base station antenna and reflected at the ceiling, and then arriving at the terminal station antenna. These waves are so-called short-delay interference waves having a short difference from the propagation time of a wave directly arriving at the terminal station antenna from the base station antenna (this is called a delay time).
[0006]
FIG. 9 is a diagram showing a conventional indoor high-speed wireless communication device and a propagation path of a long-delay interference wave. In this figure, numerals 1 to 10 are used in common with FIG. The radiation directivity from the base station antenna is directed not only to the terminal station antenna facing the device but also to the wall or ceiling behind the terminal station antenna.
[0007]
For this reason, the wave arriving from the base station antenna to the terminal station antenna is radiated from the base station antenna indicated by the numeral 17, reflected on the wall behind the terminal station antenna, and reflected again on the wall behind the base station antenna, The wave arriving at the terminal station antenna, reflected on the ceiling near the base station antenna indicated by 18, reflected on the wall behind the terminal station antenna, and again reflected on the wall behind the base station antenna, and then arrived at the terminal station antenna There are waves that do.
[0008]
These waves are so-called long delay interference waves. For this reason, in the indoor high-speed wireless communication device, the reception level is lowered due to the interference of the single reflected wave from the floor, ceiling, and side walls, which are short-delay interference waves, and the wall behind the terminal station antenna, which is a longer-delay interference wave, And two or more reflected waves reflected by the wall behind the base station antenna interfere with each other, causing a code error and deteriorating transmission characteristics.
[0009]
That is, in indoor high-speed digital transmission using a quasi-millimeter wave band or a millimeter wave band whose transmission speed reaches several tens of Mbit / s, the delay time of the interference wave is almost equal to the symbol length, and the delay time of the interference wave is the symbol length. Present inside and outside. In such an indoor multipath environment, the code error rate does not depend on the delay time of the interference wave, and the ratio (D / U) of the reception level (D) of the desired wave to the total reception level (U) of the interference wave ).
[0010]
(Literature: Nakayama, Sato, Yoshida: "High-speed indoor transmission characteristics using millimeter waves", IEICE (B), vol.77-C-I, no.11. Pp.640-647, Nov.1994)
For this reason, in indoor high-speed digital transmission in the millimeter wave band where the transmission speed reaches several tens of Mbit / s, it can be said that improving the D / U of a desired wave with respect to a large number of interference waves is the basis for realizing indoor high-speed communication. . "
[0011]
In order to improve the deterioration of the transmission characteristics due to the interference of the reflected waves reflected two or more times at the walls behind the terminal station antenna and the base station antenna, the incoming wave is absorbed by the indoor wall, By suppressing all reflected waves from the opposing wall or ceiling, or by forming a null point at an angle that looks into the opposing wall or ceiling when viewed from the base station antenna in the vertical in-plane radiation pattern, It is easily conceivable that D / U for the interference wave can be improved by suppressing all reflected waves.
[0012]
Conventionally, a radio anechoic room has been disclosed as an example of a room satisfying this condition. On the other hand, a so-called cosecant square shaped beam antenna or the like, in which a radiation pattern in a vertical plane has a cosecant square shape, is disclosed as an example of an antenna realizing an antenna having a radiation pattern shape satisfying this condition.
[0013]
FIG. 10 is a diagram showing interference wave suppression burying in a conventional anechoic chamber. In the figure, (a) shows a radio anechoic chamber, (b) shows a radio anechoic chamber, and numeral 1 denotes a floor, 2 denotes a wall behind a base station antenna, and 3 denotes a wall behind a terminal station antenna. Walls, 4 are ceilings, 5 is a base station device, 6 is a terminal device, 7 is a base station antenna, 8 is a terminal station antenna, 9 is a radiation pattern in the vertical plane of the base station antenna, and 10 is a vertical plane of the terminal station antenna. A radiation pattern 27 in the figure indicates a radio wave absorbing surface.
[0014]
In this figure, the path indicated by a solid line indicates an actual propagation path, and the broken line indicates a propagation path when radio waves that are not reflected are reflected.
Usually, the radiation directivity from the base station antenna is directed not only to the terminal station antenna facing the terminal station but also to the wall or ceiling behind the terminal station antenna.
[0015]
Therefore, as waves arriving from the base station antenna to the terminal station antenna, in addition to the direct waves arriving at the terminal station antenna after being radiated from the 14 base station antennas, the waves radiated from the 15 base station antennas and After being reflected to the terminal station antenna, and waves radiated from the 16 base station antennas and reflected from the ceiling and then arriving at the terminal station antenna,
[0016]
Further, it is radiated from the base station antenna, reflected by the wall behind the terminal station antenna, reflected again by the wall behind the base station antenna, and then arriving at the terminal station antenna and on the ceiling near the base station antenna of 18. After reflection, reflection at the wall behind the terminal station antenna, and again reflection at the wall behind the base station antenna, there is normally a wave arriving at the terminal station antenna.
[0017]
However, in the radio anechoic room, since all surfaces of the wall, ceiling and floor are radio wave absorbing surfaces composed of radio wave absorbers, the radio wave is radiated from the base station antenna indicated by the numeral 14 and then directly transmitted to the terminal station antenna. Waves radiated from the base station antenna other than the direct wave arriving at the point are first absorbed on the wall, ceiling, or floor, are absorbed by the radio wave absorbing surface, and are reflected on the wall, ceiling, or floor. The section indicated by the dashed line of the normal propagation path no longer exists.
[0018]
That is, in the radio wave anechoic room, all interference waves are suppressed at the time of first arrival at the wall surface by not reflecting on all surfaces of the wall, ceiling, and floor.
In particular, a radio anechoic room that allows reflection of the floor surface corresponding to the earth to simulate an outdoor environment and does not reflect off ceilings and walls other than the floor is shown in FIG. 10B as a radio anechoic room. The second reflection point (reflection point on the first ceiling and wall after reflection on the floor surface) is reflected by the floor reflection wave, and the other reflection wave is reflected by absorbing the radio wave at the first reflection point. Suppress waves.
[0019]
[Problems to be solved by the invention]
However, in order to realize the above-described anechoic chamber, it is necessary to construct the entire wall surface. Therefore, the scale of the construction becomes very large, and it is not practical to make ordinary offices, living rooms, classrooms, etc. rooms as radio anechoic rooms, except in special cases, in terms of space and economy. is not.
[0020]
Further, in order to realize a desired radiation pattern with a shaped beam antenna, at least several tens of element antennas are required, so that the entire antenna device including the feed circuit becomes very large.
In addition, in the shaped beam antenna, since the ratio of the excitation amplitude between the elements becomes large, the error due to the manufacturing accuracy cannot be ignored, and especially in the millimeter wave band, the effect of the manufacturing accuracy becomes remarkable, and the desired performance can be realized. There is a problem that it becomes difficult.
[0021]
As described above, the construction of a radio anechoic room is very large, and it is economically difficult to use the radio anechoic room as a normal room. In addition, in the conventional indoor wireless communication apparatus, a shaped beam antenna is used as a base station antenna, so that the number of elements constituting the array increases, and the entire antenna apparatus increases. There has been a problem that it is difficult to achieve desired performance.
[0022]
With respect to the above-mentioned problems related to the indoor high-speed wireless communication of the present invention, by suppressing reflected waves from the wall or ceiling behind the receiving antenna one or more times, multipath fading due to long-delay reflected waves is reduced, By greatly improving the ratio (D / U) between the reception level (D) of the desired wave and the total reception level (U) of the interference waves, high-quality indoor wireless communication can be realized with a wireless communication device having a simple antenna configuration. It is intended to be.
[0023]
[Means for Solving the Problems]
According to the invention, the above-mentioned problem is solved by the means described in the claims.
[0024]
That is,The basic structure of the claimed invention is as follows:In a system for performing wireless communication between at least one base station and at least one terminal station in a space such as an indoor space between two opposing wall surfaces, the wall surface arrives at least once from the base station antenna to the terminal station antenna. Using a long-delay-wave propagation blocking method that suppresses reflection of the reflected long-delay wave at any one of the reflection points on the propagation path before the terminal station antenna arrives,
[0025]
Limit the range for suppressing the reflection required to block long-delayed waves to a specific range that is the least common, and make the walls in that range a material that absorbs radio waves or a material with a small reflection coefficient, or absorbs radio waves This is a wireless communication space configured by covering with a member made of a material or a material having a small reflection coefficient.The specific configuration is shown below.
[0026]
Claim 1The present invention is directed to a system for performing wireless communication between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel, wherein the base station antenna is a wall BWallWhen the distance between the opposing walls formed by the walls A and B is L, the height from the floor to the terminal station antenna is Hr, and the height from the floor to the base station antenna is Ht ,
[0027]
The height from the floor obtained by using the H of the transmission / reception height difference given by H = Ht−Hr is represented by “Table5The range on the wall surface of the wall A and the wall B represented by any one of the item numbers 1 to 5 is made of a material absorbing radio waves or a material having a small reflection coefficient, or Panels made of material, wallpaperOrThis is a wireless communication space configured by covering with paint.
[0028]
【table5]

[0029]
Claim 2The present invention provides a system for performing wireless communication between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel, wherein the system comprises a wall A and a wall B. The distance between the walls, that is, the length of the room, is L, A is one or more real numbersWhere L / a is the distance between the base station antenna and the opposite wall (wall A) of the room, Hr is the height from the floor to the terminal station antenna, and Ht is the height from the floor to the base station antenna. When
[0030]
When the height a from the floor is 5/4 ≦ a ≦ 5, which is obtained by using the transmission / reception height difference H given by H = Ht−Hr.6Item number1, If 1 <a <5/4, “Table6Item number2-4, If 5 <a, “Table6Item number5-7The range on the wall surface of the wall A and the wall B, which is represented by any one of the above, is made of a material that absorbs radio waves or a material having a small reflection coefficient, or a panel or wallpaper made of the above materialOrThis is a wireless communication space configured by covering with paint.
[Table 6]

[0031]
Claim 3The present invention relates to multipath interference due to wall reflection or the like in a wireless communication space in which wireless communication is performed between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel. When the influence of ceiling reflection is large, the base station antennaWallAnd the distance between the opposing walls composed of the wall A and the wall B is L, the height of the ceiling is h, the height from the floor to the terminal station antenna is Hr, and the height from the floor to the base station antenna is H When the height is Ht,
[0032]
SaidClaim 1In addition to the wall surface in the range of the height from the floor indicated by, the range of the height from the floor determined using H of the mirror image transmission / reception height difference of the ceiling reflection given by H = 2h-Ht-Hr is shown in FIG.7A panel made of a material that absorbs radio waves or a material having a small reflection coefficient, or a panel made of the above material, wallpaperOrThis is a wireless communication space configured by covering with paint.
[Table 7]

[0033]
Claim 4The present invention relates to multipath interference due to wall reflection or the like in a wireless communication space in which wireless communication is performed between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel. When the influence of ceiling reflection is large, the distance between the opposing walls composed of the wall A and the wall B, that is, the length of the room is L,a is one or more real numbers,L / a is the distance between the base station antenna and the opposing wall (wall A) of the room, h is the height of the ceiling, H is the height from the floor to the terminal station antenna, and H is the height from the floor to the base station antenna. Ht,
[0034]
SaidClaim 2In addition to the wall surface in the range of the height from the floor indicated by, the range of the height from the floor obtained using H of the mirror image transmission and reception height difference of the ceiling reflection given by H = 2h-Ht-Hr is a Is 5/4 ≦ a ≦ 5, “Table8Item number1, If 1 <a <5/4, “Table8Item number2-4, If 5 <a, “Table8Item number5-7The range on the wall surface of the wall A and the wall B, which is represented by any one of the above, is made of a material that absorbs radio waves or a material having a small reflection coefficient, or a panel or wallpaper made of the above materialOrThis is a wireless communication space configured by covering with paint.
[Table 8]

[0035]
Claim 5In the wireless communication space according to claims 1 to 5, a window that reflects a radio wave such as a shield glass is included on a wall corresponding to a range constituted by a material that absorbs a radio wave or a material having a small reflection coefficient. In the case where the radio wave is absorbed, or the range corresponding to the range composed of the material with a small reflection coefficient is made of glass, etc., which transmits the radio wave and has a small reflection coefficient, or the reflection coefficient that absorbs the radio wave Panels and wallpaper made of small materialsOrIt is constructed by covering with paint.
[0036]
Claim 6The invention of the wireless communication space according to claims 1 to 5, wherein a material having a low reflection coefficient to absorb radio waves on a wall corresponding to a range constituted by a material that absorbs radio waves or a material having a low reflection coefficient, or The structure is such that it is covered with a shielding curtain such as a curtain or a blind made of a material having a small reflection coefficient.
[0037]
Claim 7In the wireless communication space according to any one of claims 1 to 5, a material having a small reflection coefficient or a low reflection coefficient for absorbing a radio wave on a wall corresponding to a range constituted by a material that absorbs a radio wave or a material having a small reflection coefficient. Or a panel or wallpaper made of the above materialsOrIt is structured to be covered with furniture such as a library, fence, partition, etc. covered with paint.
[0038]
As described above, the present invention provides a system for performing wireless communication between at least one base station and at least one terminal station in a space such as an indoor space sandwiched between two wall surfaces facing in parallel. Suppress the reflection at the first reflection point of the long-delayed wave reflected from the wall at least once arriving at the terminal station antenna from the obstructing base station antenna,
[0039]
Instead of blocking propagation of the long delay wave to the terminal station antenna, a long delay wave propagation blocking method is used, which suppresses reflection at any reflection point in the propagation path before the terminal station antenna arrives. Is limited to a specific range that is minimum common.
[0040]
Furthermore, by utilizing the geometrical feature that the walls of the room are parallel, the propagation path with the greater number of reflections in the vertical plane when the terminal station antenna arrives will have a narrower radiation angle width from the base station antenna, The range of the reflection points on the wall in the middle of propagation is narrower for the propagation path with the higher number of reflections, the majority is the reflection points on the wall in the middle of propagation, and the range of the reflection points on the wall of the propagation path with the lower number of reflections is wider Utilizing the feature that there is a reflection point included in
[0041]
The range of the wall surface including at least one reflection point on the propagation path of all the long delay waves in question is specified to a minimum, and the wall surface in the range is made of a material absorbing radio waves or a material having a small reflection coefficient. Thereby, without improving the wireless communication apparatus itself, the propagation of the long delay wave to be suppressed to the terminal station antenna is cut off, the multipath fading due to the long delay reflected wave is reduced, and the reception level (D) of the desired wave is reduced. The ratio (D / U) to the reception level (U) of the interference wave is greatly improved, and high-quality wireless communication can be performed.
[0042]
In the related art, since the propagation path of the long delay wave to be suppressed is not considered, the long delay wave is suppressed as in the radio anechoic chamber and the semi-anechoic chamber described in the section of the related art. As a means for performing this, all reflected waves are suppressed during the first or second wall reflection. For this reason, there has been a problem that the area of the wall surface that does not reflect the radio wave necessary for suppressing the long delay wave becomes very large.
[0043]
Unlike a radio anechoic chamber or a radio anechoic chamber, it prevents all wall reflections and does not necessarily absorb radio waves at the first or second reflection point, but arrives from the base station antenna to the terminal station antenna. The long delay wave to be suppressed, which has been reflected on the wall at least once, can be suppressed unless reflected at any reflection point on the propagation path before the terminal station antenna arrives.
[0044]
By using this principle, the range of the wall surface that does not reflect radio waves is limited, and even if the area is very small, long delay waves can be suppressed and D / U can be improved. This is a point different from the prior art of the present invention.
[0045]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail as examples with reference to the drawings.
FIG. 1 is a diagram showing a first embodiment of the present invention. In the figure, numeral 1 indicates a floor, 2 indicates a wall behind a base station antenna (wall B), 3 indicates a wall behind a terminal station antenna (wall A), 4 indicates a ceiling, 5 indicates a base station apparatus, and 6 indicates a terminal station. The device, 7 is a base station antenna, 8 is a terminal station antenna, and 9 is a radiation pattern in a vertical plane of the base station antenna.
[0046]
In addition, 10 is a radiation pattern in the vertical plane of the terminal station antenna, 12 is a wall portion made of a material that absorbs radio waves or a material with a small reflection coefficient, and 13 is a material that absorbs radio waves or a material with a small reflection coefficient , Represents a propagation path of a wave arriving at the terminal station antenna directly from the base station antenna.
[0047]
Further, the wave 17 is reflected from the base station antenna on the wall 3 behind the terminal station antenna, reflected on the wall 2 behind the base station antenna, and then arriving at the terminal station antenna (the broken line section is reflected within the range not reflected). The propagation path (18) is reflected from the base station antenna on the ceiling 4, reflected on the wall 3 behind the terminal station antenna, further reflected on the wall 2 behind the base station antenna, and then arriving at the terminal station antenna ( A broken line section indicates a propagation path when light is reflected in a range where light is not reflected.
[0048]
In the actual radio wave propagation of the present invention, there is no propagation in the dashed sections of the

propagation paths

17 and 18 because it is not reflected at the

wall portions

12 and 13.
FIG. 2 is a diagram illustrating the arrangement of the opposing wall and the base station antenna according to the present invention.
FIG. 2A shows the distance between the wall A and the wall B perpendicular to the floor as L, the height of the ceiling as h, the height from the floor to the base station antenna as Ht, and the height from the floor to the terminal station antenna. FIG. 9 is a vertical sectional view when the base station antenna is installed near the wall B, where is Hr.
[0049]
FIG. 2B shows the distance between the wall A and the wall B perpendicular to the floor as L, the height of the ceiling as h, the height from the floor to the base station antenna as Ht, and the height from the floor to the terminal station antenna. Is a vertical sectional view when the base station antenna is disposed between the walls, where H is the distance between the base station antenna and the opposite wall (wall A) surface of the room, where L / a (where 1 ≦ a <∞). It is.
[0050]
FIG. 3 is a diagram illustrating the value of the height difference H and the transmission height T according to the present invention.
FIG. 3A is a vertical sectional view showing a normal transmission / reception height difference H and a transmission height T. The distance between the opposing walls composed of the wall A and the wall B is the length L of the room, and the distance between the base station antenna and the opposing wall (wall A) surface is L / a (where 1 ≦ a <∞). When the height from the floor to the terminal station antenna is Hr and the height from the floor to the base station antenna is Ht,
[0051]
H = Ht-Hr (Expression of transmission / reception height difference)
Can be easily obtained.
Transmission height T is equal to transmission point height Ht
T = Ht = H + Hr
Can be obtained as
[0052]
FIG. 3B is a vertical sectional view showing a mirror image transmission / reception height difference H and a transmission height T due to ceiling reflection.
The distance between the opposing walls formed by the walls A and B is the length of the room L, and the distance between the base station antenna and the opposing wall (wall A) of the room is L / a (where 1 ≦ a <∞). ), When the height from the floor to the terminal station antenna is Hr and the height from the floor to the base station antenna is Ht,
[0053]
H = 2h-Ht-Hr (Expression of the mirror image transmission / reception height difference of ceiling reflection)
And can be easily obtained.
The transmission height T is considered in consideration of the case of the mirror image transmission point.
T = H + Hr
Can be obtained as
[0054]
FIG. 4 is a plan view showing the positional relationship between the base station antenna of the present invention and a wall.
The direction of the room width (wall B'-wall A ') is defined as the X-axis direction, and the width of the room is defined as Lx. The direction of the depth of the room (wall B "-wall A") is the Y-axis direction, and the depth of the room is Ly. The distance between the base station antenna and the room wall A ′ plane is Lx / b (1 ≦ b <∞), and the distance between the base station antenna and the room wall A ″ plane is Ly / c (1 ≦ c <１). Can be represented.
[0055]
FIG. 5 is a vertical view illustrating the positional relationship between the opposing wall and the base station antenna according to the present invention.
Usually, since the partially considered indoor shape is considered to be a rectangular parallelepiped, the indoor is considered as rectangular coordinates (XYZ coordinates), the width direction of the room is the X direction, the depth direction of the room is the Y direction, and the vertical direction is the Z direction. Then, a change in the vertical direction (Z-axis direction) of radio wave propagation can be decomposed into an XZ coordinate component and a YZ coordinate component.
[0056]
FIG. 5A is a vertical sectional view in the x-axis direction of FIG.
FIG. 5B is a vertical sectional view in the Y-axis direction of FIG.
X-axis section and Y-axis section in FIG.surfaceAre generalized into walls A and B, and the distance between the walls A and B is represented by L, and the distance between the base station antenna and the wall A of the room is represented by L / a (where 1 ≦ a <∞). be able to.
[0057]
FIG. 6 is a diagram illustrating the formulation of the range of the wall surface that does not reflect radio waves according to the first embodiment of this invention.
T is the transmission height, L is the distance between the wall A and the wall B perpendicular to the floor, H is the mirror image transmission / reception height difference, and Hr is the height from the floor to the terminal station antenna. It is the figure which connected and showed the same vertical sectional view at the time of installation. The transmission height T is considered in consideration of the case of the mirror image transmission point.
T = H + Hr
Can be easily stopped.
[0058]
The problem with the reflected wave that becomes a long delay wave is that the arrival direction to the terminal station antenna is in the same direction as the direct wave (from wall B to wall A), and finally the wall (wall B) behind the base station antenna After the reflection, the reflected wave arrives at the terminal station antenna and is reflected by the wall A and the wall B an even number of times.
[0059]
After being radiated from the base station antenna, reflected on the wall (wall A) behind the terminal station antenna, and reflected on the wall (wall B) behind the base station antenna, the receiving point of the twice reflected wave arriving at the terminal station antenna is The range of the horizontal distance from the transmission point is 2L to 3L, and the line connecting the transmission point, the reception point of the wall B, and the reception point of the wall A has a height difference H with respect to the wall B and the wall A parallel at L intervals. Since it intersects the point divided into two equal parts and three equal parts, the range of the wall surface which becomes the reflection point of the twice reflected wave is 1/2 to 2/3 of the height difference H in the wall A, and 0 to 0 in the height difference H in the wall B. It is in the range of 1/3.
[0060]
Similarly, the reception point of the four reflection waves has a horizontal distance range from the transmission point of 4L to 5L. Therefore, the lines connecting the transmission point, the reception point of the wall B, and the reception point of the wall A are the wall B and the wall A. Intersects with a point obtained by dividing the height difference H into four equal parts and five equal parts, and the receiving point of the six times reflected wave has a horizontal distance range from the transmitting point of 6L to 7L. A line connecting the receiving point and the receiving point of the wall A intersects a point obtained by dividing the height difference H into six and seven parts with respect to the wall B and the wall A.
[0061]
Accordingly, the reception point of the 2n reflection waves has a horizontal distance range from the transmission point of 2 nL to (2n + 1) L, and the line connecting the transmission point and the reception point of the wall A and the reception point of the wall B is the wall B, The height difference H intersects with the point obtained by equally dividing the height difference H by 2n and (2n + 1) with respect to the wall A, and the range of the reflection point at the m-th wall A of the 2n reflection wave is
[0062]
(2 (nm) +1) H / 2n to 2 (nm + 1) H / (2n + 1)
(However, m is a natural number less than or equal to n)
Can be asked,
The range of the reflection point on the m-th wall B of the 2n reflection wave is
(Nm) H / n-(2 (nm) +1) H / (2n + 1)
(However, m is a natural number less than or equal to n)
You can ask.
[0063]
From the range of the reflection points on the walls A and B of the 2n reflected waves obtained above, the range necessary for suppressing the 2n reflected waves at the wall reflection points on the propagation path can be classified as follows. .In addition, Table 9 shows a summary of the above Tables 5 to 8.
[Table 9]
(However, a is one or more real numbers.)

[0064]
(1) When suppression is performed at the reflection points on both the wall A wall and the wall B wall
(Suppressed at the intermediate reflection point of the propagation path)
(First reflection point of twice reflected wave on wall A wall, first reflection point of four times reflected wave on wall B wall)
(I)Equal range of wall A wall and wall B wall9(Item No. 1 of "
(B)The range covering the midpoint of all 4n-2 reflected waves on the wall A wall and the midpoint of all 4n reflected waves on the wall B wall ("Table9(Corresponds to item number 2 of ")
[0065]
(2) When suppression is performed only at the reflection point on the wall A wall
(Suppressed at the reflection point in the first half of the propagation path)
A continuous range that suppresses the reflection points of the twice reflected wave and the four reflected waves
(C)A continuous range including the first reflection point of the twice reflected wave and the fourth reflected wave on the wall A (“Table9No. 3 of ") is equivalent)
(D)A continuous range including the first reflection point of the second reflection wave and the second reflection point of the fourth reflection wave on the wall A ("Table9Item No. 4 of "is equivalent)
[0066]
(3) When suppression is performed only at the reflection point on the wall B
(Suppressed at the last reflection point in the propagation path)
(E)The range of the last reflection point of the twice reflected wave on the wall B ("Table9No. 5 of "" is equivalent)
Divided into
[0067]
FIG. 7 is a diagram for explaining the formulation of the range of the wall surface that does not reflect radio waves according to the second embodiment of the present invention.
In the figure, T is the transmission height, L is the distance between the walls A and B perpendicular to the floor, L / a is the distance between the base station antenna and the opposing wall (wall A) of the room, and h is the ceiling. The height, Ht, is the height from the floor to the base station antenna, and Hr is the height from the floor to the terminal station antenna. The figure is a diagram in which eight such rooms having the same vertical cross section are connected. It is.
[0068]
In FIG. 7, room 0 is a real image, rooms 1 to 6 are mirror images, and room -1 is a room at a mirror image transmission point on a horizontal plane. The broken line is a line indicating the horizontal position of the transmission point and the mirror image transmission point of each room. The transmission height T is given in consideration of the case of the mirror image transmission point.
T = H + Hr
Can be easily stopped.
The problem with the reflected wave that is a long delay wave is a reflected wave that reciprocates on walls A and B and arrives at the terminal station antenna, the direction of arrival at the terminal station antenna being the same as the direct wave.
[0069]
When the base station antenna is installed between the wall A and the wall B, not only the even number of reflections finally reflected on the wall behind the base station antenna (wall B), but also the wall behind the terminal station antenna finally The odd number of reflected waves reflected by (wall A) also have the same direction of arrival at the terminal station antenna as the direct wave in the range from the base station antenna position to the wall (wall B) behind the base station antenna.
Considering propagation in the case where only the direction of the wall A is radiated from the transmitting antenna, an odd-number reflected wave exists only when the room number is odd, and an even-number reflected wave exists only when the room number is even.
[0070]
After being radiated from the base station antenna and reflected on the wall (wall A) behind the terminal station antenna and arriving at the terminal station antenna, the reception point of the once-reflected wave is the reception on the line indicating the horizontal position of the mirror image transmission point of the room 1 In the range from the point to the reception point on the wall B, the range of the horizontal distance from the transmission point is 2L / a to (a + 1) L / a, and the line connecting the start and end boundary points of the transmission point and the reception point is: Since the height difference H intersects the wall A in a divided manner, the range of the wall surface which is the reflection point of the once-reflected wave is 1/2 to a / (a + 1) of the height difference H on the wall A.
[0071]
The receiving point of the three reflected waves is a range from the receiving point on the line indicating the horizontal position of the mirror image transmitting point of the room 3 to the receiving point of the wall B, and the range of the horizontal distance from the transmitting point is L (2a + 2) / a. 3L (a + 1) / a, and the line connecting the start and end boundary points of the transmission point and the reception point intersects the wall A by dividing the height difference H, so that the wall surface becomes the reflection point of the reflected wave three times Ranges from (2a + 1) / (2a + 2) to 3a / (3a + 1) of the height difference H at the first reflection on the wall A, 1 / (2a + 2) to a / (3a + 1) of the height difference H at the second reflection. At B, the height difference is in the range of 1/2 to 2a / (3a + 1).
[0072]
Similarly, the reception point of the reflected wave five times is a range from the reception point on the line indicating the horizontal position of the mirror image transmission point of the room 5 to the reception point of the wall B, and the range of the horizontal distance is L (4a + 2) / a to L ( 5a + 1) / a.
That is, the range of the horizontal distance from the transmission point to the mirror image reception point of the odd-numbered n-times reflected wave is
((N-1) a + 2) L / a to (na + 1) L / a
(However, n = 2Q−1 and Q is a natural number).
[0073]
Therefore,
The range of the reflection point at the m-th wall A of the odd-numbered n-times reflected wave is
(A (n-2m + 1) +1) H / ((n-1) a + 2) to a (n-2m + 2) H / (na + 1)
(Where m is a natural number less than or equal to Q, n = 2Q-1 and Q is a natural number)
[0074]
The range of the reflection point on the m-th wall B of the odd-numbered n-times reflected wave is
(A (n−2m) +1) H / ((n−1) a + 2) to a (n−2m + 1) H / (na + 1)
(Where m is a natural number less than Q, n is 2Q-1 and Q is a natural number).
[0075]
Next, consider an even number of reflected waves.
Receiving point of the twice reflected wave radiated from the base station antenna, reflected on the wall (wall A) behind the terminal station antenna, reflected on the wall (wall B) behind the base station antenna, and arriving at the terminal station antenna Is a range from the reception point on the line indicating the horizontal position of the mirror image transmission point of the room 2 to the reception point on the wall A, and the range of the horizontal distance is 2L to (2a + 1) L / a,
[0076]
The line connecting the start and end boundary points of the transmission point and the reception point intersects the wall A and the wall B by dividing the height difference H. Therefore, the range of the wall which is the reflection point of the twice reflected wave is the wall A The height difference H ranges from (2a-1) / 2a to 2a / (2a + 1), and the wall B has a height difference H ranging from (a-1) / 2a to a / (2a + 1).
[0077]
The receiving point of the four reflection waves is a range from the receiving point on the line indicating the horizontal position of the mirror image transmitting point of the room 4 to the receiving point of the wall A, and the horizontal distance range is 4L to (4a + 1) L / a. And the line connecting the start and end boundary points of the receiving point intersects the wall A and the wall B by dividing the height difference H,
[0078]
The range of the wall surface which becomes the reflection point of the four times reflected wave is (4a-1) / 4a to 4a / (4a + 1) of the height difference H at the first reflection of the wall A, and (((a)) of the height difference H at the second reflection. 2a-1) / 4a to 2a / (4a + 1), (3a-1) / 4a to 3a / (4a + 1) of the height difference H at the first reflection of the wall B, and (a) of the height difference H at the second reflection. -1) / 4a to a / (4a + 1).
[0079]
Similarly, the reception points of the six times reflected wave are from the reception point on the line indicating the horizontal position of the mirror image transmission point of the room 6 to the reception point of the wall B, and the horizontal distance range is 6L to (6a + 1) L / a. Become.
That is, the range of the horizontal distance from the transmission point to the mirror image reception point of an even-numbered n-times reflected wave is
nL to (na + 1) L / a
(However, n is 2Q and Q is a natural number)
It becomes.
[0080]
Therefore,
The range of the reflection point on the m-th wall A of the even-numbered n-times reflected wave is
(A (n-2m) +2) -1) H / na to a (n-2m + 2) H / (na + 1)
(However, m is a natural number less than or equal to Q, n = 2Q and Q is a natural number)
You can ask.
[0081]
Furthermore, in order to consider the propagation when radiating from the transmitting antenna in the direction of the wall B, when radiating from the mirror image transmission point on the horizontal plane of room number -1, the odd number of reflected waves is only when the room number is even. There is an even-numbered reflected wave only when the room number is odd.
[0082]
The range of the horizontal distance of the mirror image receiving point of the odd-numbered reflected waves from the mirror image transmitting point when radiating in the wall B direction is
(Na + a-2) L / a to (na + a-1) L / a
(However, n = 2Q-1 and Q is a natural number)
Becomes
The range of the horizontal distance from the mirror image receiving point of the n-times reflected wave from the mirror image transmitting point is
nL to (na + a-1) L / a
(However, n is 2Q and Q is a natural number)
It becomes.
[0083]
Therefore,
The range of the reflection point at the m-th wall A of the odd-numbered n-times reflected wave when radiated in the direction of the wall B is
(A (n-2m) +1) -1) H / (na + a-2) to a (n-2m + 1) H / (na + a-1)
(Where m is a natural number less than Q, n = 2Q-1 and Q is a natural number)
[0084]
The range of the reflection point at the m-th wall B of the odd-numbered n-times reflected wave when radiated in the wall B direction is
(A (n-2m + 2) -1) H / (na + a-2) to a (n-2m + 2) H / (na + a-1)
(Where m is a natural number less than or equal to Q, n = 2Q-1 and Q is a natural number).
[0085]
Next, consider an even number of reflected waves.
The range of the reflection point on the m-th wall A of the even-numbered n-times reflected wave when radiated in the direction of the wall B is
(A (n−2m) +1) H / na to (n−2m + 1) H / (na + a−1)
(However, m is a natural number less than or equal to Q, n = 2Q and Q is a natural number)
[0086]
The range of the reflection point at the m-th wall B of the even-numbered n-times reflected wave when radiated in the wall B direction is
(A (n−2m + 1) +1) H / na to a (n−2m + 2) H / (na + a−1) (where m is a natural number less than or equal to Q, and n = 2Q and Q is a natural number).
[0087]
The reflected wave is suppressed at the wall reflection point on the propagation path from the range of the reflection points on the wall A and the wall B when the light is radiated in the direction of the wall A and the wall B from the transmission points of the walls A and B obtained above. The necessary range can be divided into the following cases.
[0088]
(1) When the position L / a of the transmitting antenna from the wall A is 5/4 ≦ a ≦ 5
(Range of the first reflection point of one or two reflected waves on wall A wall and the first reflection point of one or two reflected waves on wall B wall)
(I)When the transmitting antenna position L / a is 5/4 ≦ a ≦ 5
On the wall A wall side, the first reflection point on the wall A wall which is first reflected by the wall A and becomes a reflected wave once or twice is continuously covered, and on the wall B wall surface side, the first reflection point is reflected by the wall B first. A range that continuously covers the first reflection point on the wall B, which becomes the reflected wave once or twice (“Table9Item number1)
[0089]
(2) When the transmitting antenna position L / a from the wall A is 1 <a <5/4
(Reflection point of 1-2 reflection waves reflected first on wall A, reflection point of 1-4 reflection waves reflected first on wall B)
(B)On the wall surface of the wall A, the first reflection point on the wall surface of the wall A, which is first reflected by the wall A and becomes a reflected wave once or twice, and the reflected wave which is first reflected by the wall B and becomes a reflected wave of three to four times The first reflection point on the wall surface of the wall B where the first reflection point on the wall surface of the wall A continuously reflects the first reflection point on the wall surface of the wall B and becomes the reflected wave once or twice on the wall surface side of the wall B Range (“Table9Item No. 7)
[0090]
(C)On the wall side of the wall A, the range that continuously covers the first reflection point on the wall surface of the wall A, which first reflects on the wall A and becomes a reflected wave once or twice, Range that continuously covers the first reflection point on the wall B, which is reflected to the surface and becomes a reflected wave 1 to 4 times (“Table9Item No. 8)
(Reflection point of the first or second reflection wave reflected first on wall A, reflection point of the first or second reflection wave reflected first on wall B, and second reflection point of the fourth reflection wave)
[0091]
(D)On the wall side of the wall A, the range that continuously covers the first reflection point on the wall surface of the wall A, which first reflects on the wall A and becomes a reflected wave once or twice, The first reflection point on the wall surface of the wall B, which is reflected once and twice as reflected wave, and the second reflection point on the wall surface of the wall B of the reflected wave first reflected on the wall B and becomes four times reflected wave Continuous coverage ("Table9Item number9)
[0092]
(3) When transmitting antenna position L / a from wall A is 5 <a
(Reflection point of 1 to 4 times reflected wave reflected first on wall A, reflection point of 1 to 2 times reflected wave reflected first on wall B)
(E)On the wall side of the wall A, the range that continuously covers the first reflection point on the wall surface of the wall A, which first reflects on the wall A and becomes a reflected wave once or twice, The first reflection point on the wall surface of the wall B where the first reflection point on the wall surface of the wall B becomes a reflected wave once or twice and the reflection wave which is first reflected on the wall A and becomes the reflection wave of three or four times Range (“Table9Item No. 10)
[0093]
(F)On the wall side of the wall A, the range that continuously covers the first reflection point on the wall surface of the wall A, which first reflects on the wall A and becomes a reflected wave 1 to 4 times, Range that continuously covers the first reflection point on the wall B wall which is reflected once or twice as reflected waves9Item number 11)
(Reflection point of first or second reflection wave reflected first on wall A, second reflection point of fourth reflection wave, reflection point of first or second reflection wave reflected first on wall B)
[0094]
(G)On the wall A wall side, the first reflection point on the wall A wall which is first reflected by the wall A and becomes a reflected wave once or twice and the wall of the reflected wave which is first reflected by the wall A and becomes a reflected wave four times The range that continuously covers the second reflection point on the wall A is defined as the first reflection point on the wall B where the wall B first reflects on the wall B and becomes a reflected wave once or twice. Continuous coverage ("Table9Item No. 12)
[0095]
FIG. 8 is a diagram illustrating a conventional indoor high-speed wireless communication device and a propagation path of a short-delay interference wave. In the figure, numeral 1 is a floor, 2 is a wall behind a base station antenna, 3 is a wall behind a terminal station antenna, 4 is a ceiling, 5 is a base station device, 6 is a terminal device, 7 is a base station antenna, 8 is a terminal antenna,
[0096]
9 is a radiation pattern in the vertical plane of the base station antenna, 10 is a radiation pattern in the vertical plane of the terminal station antenna, 14 is a propagation path of a wave arriving directly at the terminal antenna from the base station antenna, and 15 is a propagation path from the base station antenna. The propagation path of the wave radiated and reflected on the floor and arriving at the terminal antenna, and 16 is the propagation path of the wave radiated from the base station antenna and reflected on the ceiling and arriving at the terminal antenna.
[0097]
FIG. 9 is a diagram showing a conventional indoor high-speed wireless communication device and a propagation path of a long-delay interference wave. In the figure, numeral 1 is a floor, 2 is a wall behind a base station antenna, 3 is a wall behind a terminal station antenna, 4 is a ceiling, 5 is a base station device, 6 is a terminal device, 7 is a base station antenna, Reference numeral 8 denotes a terminal station antenna, 9 denotes a radiation pattern in a vertical plane of the base station antenna, and 10 denotes a radiation pattern in a vertical plane of the terminal station antenna.
[0098]
Reference numeral 17 denotes a propagation path of a wave reflected from the base station antenna to a wall behind the terminal station antenna, reflected from a wall behind the base station antenna, and then reaches the terminal station antenna. Reference numeral 18 denotes a reflection path from the base station antenna to the ceiling. This is a propagation path of a wave that arrives at the terminal station antenna after being reflected on the wall behind the terminal station antenna and further reflected on the wall behind the base station antenna.
[0099]
FIG. 10 is a diagram showing the principle of interference wave suppression in a conventional anechoic chamber. Numeral code 1 is a floor, 2 is a wall behind a base station antenna, 3 is a wall behind a terminal station antenna, 4 is a ceiling, 5 is a base station device, 6 is a terminal device, 7 is a base station antenna, and 8 is a terminal station. Antenna, 9 is a radiation pattern in the vertical plane of the base station antenna,
[0100]
10 is a radiation pattern in the vertical plane of the terminal antenna, 14 is a propagation path of a wave arriving at the terminal antenna directly from the base station antenna, 15 is radiated from the base station antenna, and is reflected on the floor and arrives at the terminal antenna. 16 is a propagation path of a wave that radiates from the base station antenna and is reflected by the ceiling and then arrives at the terminal antenna.
[0101]
17 is reflected from the base station antenna on the wall behind the terminal station antenna, and after being reflected on the wall behind the base station antenna, 18 is the propagation path of the wave arriving at the terminal station antenna, 18 is reflected on the ceiling from the base station antenna, The propagation path 27 of the wave that reaches the terminal station antenna after being reflected on the wall behind the terminal station antenna and further on the wall behind the base station antenna is an electric wave absorbing surface.
[0102]
FIG. 11 is a diagram showing a first embodiment of the present invention. In the figure, numeral 1 denotes a floor, 3 denotes a wall behind the terminal antenna, 4 denotes a ceiling, and 12 denotes a portion on the wall of the wall A made of a material that absorbs radio waves or a material having a small reflection coefficient. is there. This example1 shows a basic configuration of the present invention.
[0103]
FIG. 12 is a view showing a second embodiment of the present invention. In the figure, numeral 1 is a floor, 2 is a wall behind a base station antenna (wall B), 3 is a wall behind a terminal station antenna (wall A), 4 is a ceiling, and 12 is a radio wave on the wall of the wall A. A portion 13 made of a material that absorbs or has a small reflection coefficient, and 13 is a portion that is made of a material that absorbs radio waves on the wall surface of the wall B or a material that has a small reflection coefficient.
[0104]
FIG. 13 is a diagram showing a third embodiment of the present invention. In the figure, numeral 1 denotes a floor, 3 denotes a wall behind the terminal antenna, 4 denotes a ceiling, and 19 denotes a radio wave obtained by using H of a transmission / reception height difference given by an equation H = Ht-Hr. Whether it is made of a material that absorbs or has a small reflection coefficient,
[0105]
Or a panel or wallpaper composed of the above materialsOrThe range on the wall surface covered with paint, 20 is made of a material that absorbs radio waves or a material having a small reflection coefficient, which is obtained by using the mirror image transmission / reception height difference H of ceiling reflection given by the equation H = 2h-Ht-Hr. Or a panel or wallpaper made of the above materialsOrThe area on the wall that is covered with paint.
[0106]
FIG. 14 is a diagram showing a fourth embodiment of the present invention. In the figure, numeral 1 denotes a floor, 2 denotes a wall behind a base station antenna, 3 denotes a wall behind a terminal station antenna, 4 denotes a ceiling, and 19 denotes H of a transmission / reception height difference given by an equation H = Ht-Hr. It is made of a material that absorbs radio waves or has a small reflection coefficient,
[0107]
Or a panel or wallpaper composed of the above materialsOrThe range on the wall surface covered with paint, 20 is made of a material that absorbs radio waves or a material having a small reflection coefficient, which is obtained by using the mirror image transmission / reception height difference H of ceiling reflection given by the equation H = 2h-Ht-Hr. Or a panel or wallpaper made of the above materialsOrThe area on the wall that is covered with paint.
[0108]
FIG. 15 is a diagram showing a fifth embodiment of the present invention. In the same figure, numeral 1 is a floor, 4 is a ceiling, and 19 is a material that absorbs radio waves or has a small reflection coefficient, which is obtained by using H of a transmission / reception height difference given by the equation H = Ht-Hr. Panel or wallpaper made up of the above materialsOrThe area on the wall that is covered with paint.
[0109]
FIG. 16 is a view showing a sixth embodiment of the present invention. In the figure, numeral 1 denotes a floor, 4 denotes a ceiling, and 19 denotes a material that absorbs radio waves or has a small reflection coefficient, which is obtained by using H of a transmission / reception height difference given by the equation H = Ht-Hr. Configure or
[0110]
Or a panel or wallpaper composed of the above materialsOrThe range on the wall surface covered with paint, 20 is made of a material that absorbs radio waves or a material having a small reflection coefficient, which is obtained by using the mirror image transmission / reception height difference H of ceiling reflection given by the equation H = 2h-Ht-Hr. Or a panel or wallpaper made of the above materialsOrThe area on the wall that is covered with paint.
[0111]
FIG. 17 is a view showing a seventh embodiment of the present invention. In FIG.IsH = Ht−Hr, which is obtained by using the difference H between the transmission and reception heights, which is made of a material absorbing radio waves or a material having a small reflection coefficient, or a panel or wallpaper made of the above materialsOrThe area on the wall that is covered with paint.
[0112]
FIG. 18 is a view showing an eighth embodiment of the present invention. In FIG.IsH = Ht−Hr, which is obtained by using the transmission / reception height difference H, which is made of a material absorbing radio waves or a material having a small reflection coefficient, or a panel or wallpaper made of the above materialsOrArea on the wall covered with paint,
[0113]
20 is made of a material that absorbs radio waves or a material having a small reflection coefficient, which is obtained by using the mirror image transmission / reception height difference H of ceiling reflection given by the equation H = 2h-Ht-Hr, or Panels and wallpapers composed ofOrThe area on the wall that is covered with paint.
[0114]
FIG. 19 shows a ninth embodiment of the present invention. In the same figure, numeral 1 is a floor, 4 is a ceiling, 21 is a radio wave absorbing material or a material having a small reflection coefficient, or a panel or wallpaper made of the above materials.OrThe area on the wall surface covered with paint, 22 is made of glass or the like of a material having a small reflection coefficient, or a panel or wallpaper made of a material having a small reflection coefficient by absorbing radio wavesOrThe area of the window covered with the wall material of paint, 23 is a window, and 24 is a wall.
[0115]
FIG. 20 is a diagram showing a tenth embodiment of the present invention. In the figure, numeral 21 denotes a material that absorbs radio waves or a material having a small reflection coefficient, or a panel or wallpaper made of the aforementioned material.OrA range on the wall surface covered with paint, 24 is a wall, 25 is a fixture such as a library, a partition, etc., 26 is a material that absorbs radio waves of the fixture, or is made of a material having a small reflection coefficient, or absorbs radio waves. Panels and wallpapers made of materials with low reflection coefficientOrThe range of furniture covered with paint wall material.
[0116]
【The invention's effect】
As described above, the wireless communication space of the present invention causes multipath fading, which is a problem in realizing an indoor high-speed wireless communication device such as a wireless LAN, through a band-like range of a specific height on a wall surface. By using a material with a small reflection coefficient or covering it with a shielding material that absorbs radio waves, radio waves that propagate at the radiation angle that causes them are cut off at the reflection points on the propagation path without reflecting the reflected waves. It is suppressed by.
[0117]
As a result, it is possible to suppress one or more reflected waves from an opposing wall or ceiling without using an antenna having a complicated beam shaping function such as null point shaping to reduce multipath fading in the base station antenna. It is possible to reduce the multipath fading caused by the long-delay reflected wave and greatly improve the error rate (BER) and D / U (ratio of desired wave to interference wave). There is an advantage that can be realized by a wireless communication device having a simple antenna configuration.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an arrangement of opposing walls and a base station antenna.
FIG. 3 is a diagram illustrating a value of a height difference H and a transmission height T.
FIG. 4 is a plan view showing a positional relationship between a base station antenna and a wall.
FIG. 5 is a vertical plan view illustrating a positional relationship between an opposing wall and a base station antenna.
FIG. 6 is a diagram illustrating the formulation of a range of a wall surface that does not reflect radio waves according to the first embodiment.
FIG. 7 is a diagram illustrating the formulation of a range of a wall surface that does not reflect radio waves according to the second embodiment.
FIG. 8 is a diagram illustrating a conventional indoor wireless communication apparatus and a propagation path of a short-delay interference wave.
FIG. 9 is a diagram showing a conventional indoor wireless communication apparatus and a propagation path of a long-delay interference wave.
FIG. 10 is a diagram illustrating the principle of interference wave suppression in a conventional anechoic chamber.
FIG. 11 is a diagram showing a first embodiment of the present invention.
FIG. 12 is a diagram showing a second embodiment of the present invention.
FIG. 13 is a diagram showing a third embodiment of the present invention.
FIG. 14 is a diagram showing a fourth embodiment of the present invention.
FIG. 15 is a diagram showing a fifth embodiment of the present invention.
FIG. 16 is a diagram showing a sixth embodiment of the present invention.
FIG. 17 is a diagram showing a seventh embodiment of the present invention.
FIG. 18 is a diagram showing an eighth embodiment of the present invention.
FIG. 19 is a diagram showing a ninth embodiment of the present invention.
FIG. 20 is a diagram showing a tenth embodiment of the present invention.
[Explanation of symbols]
1 floor
2 Wall behind base station antenna (wall B)
3 Wall behind terminal station antenna (wall A)
4 ceiling
5 Base station equipment
6. Terminal station equipment
7 Base station antenna
8 Terminal station antenna
9 Radiation pattern in the vertical plane of the base station antenna
10. Radiation pattern in the vertical plane of the terminal station antenna
11 Transmission point (position of transmission antenna)
12, 13 A part composed of a material that absorbs radio waves on the wall surface or a material with a small reflection coefficient
14-18 Radio wave propagation path
19 ～ 21 Area on the wall where measures are taken
22 Areas on windows where measures are taken
23 windows
24 walls
25 Fixtures such as archives and partitions
26 The range of furniture to be treated
27 Radio wave absorption surface

Claims

In a system for performing wireless communication between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel,
When the base station antenna is installed on the wall surface of the wall B and the distance between the opposing walls formed by the wall A and the wall B is L, the height from the floor to the terminal station antenna is Hr, and the height from the floor to the base station antenna is H Where Ht is the height of the floor, and the height from the floor obtained using H of the transmission / reception height difference given by H = Ht−Hr is any one of the item numbers 1 to 5 in “Table 1”. , The area on the wall surfaces of the wall A and the wall B is made of a material that absorbs radio waves, or a material having a small reflection coefficient, or is covered with a panel, wallpaper, or paint made of the above materials. A wireless communication space characterized by the following.

In a system for performing wireless communication between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel,
When the distance between the opposing walls formed by the walls A and B, that is, the length of the room is L , and a is a real number of 1 or more, the distance between the base station antenna and the opposing wall (wall A) surface of the room is L. / A, when the height from the floor to the terminal station antenna is Hr, and the height from the floor to the base station antenna is Ht, it is obtained using H of the transmission / reception height difference given by H = Ht−Hr. height from floor, the value of a is, 5/4 ≦ a No. 1 when "table 2" ≦ 5, 1 <case of a <5/4, item number of "table 2" 2-4 In the case of 5 <a, the area on the wall surfaces of the wall A and the wall B represented by any one of the item numbers 5 to 7 in “Table 2 ” is made of a material that absorbs radio waves or a material having a small reflection coefficient. Or a radio communication space covered with a panel, wallpaper or paint made of the above-mentioned material.

In a wireless communication space for performing wireless communication between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel,
If the influence of the ceiling reflection Multipath interference due wall reflection or the like is large, the base station antenna is installed on the wall surface of the wall B, and a distance comprised opposing walls wall A and wall B is L, the ceiling Where H is the height from the floor to the terminal station antenna, and Ht is the height from the floor to the base station antenna, H = Ht−Hr The required height from the floor is given by the range on the wall surfaces of the wall A and the wall B represented by any one of the item numbers 1 to 5 in "Table 3 " and H = 2h-Ht-Hr. The range of the height from the floor obtained by using the mirror image transmission / reception height difference H of the reflected ceiling reflection is represented by any of the item numbers 1 to 5 of "Table 3 ". Is composed of a material that absorbs radio waves or a material with a small reflection coefficient, or Panel was composed of quality, the wireless communication space, characterized in that covered by wallpaper or paint.

In a wireless communication space for performing wireless communication between at least one base station and at least one terminal station in a space sandwiched between two wall surfaces facing in parallel,
When the influence of ceiling reflection on multipath interference due to wall reflection or the like is large, the distance between opposing walls composed of walls A and B, that is, the length of the room is L, a is a real number of 1 or more, and the base station antenna and When the distance to the opposite wall (wall A) surface of the room is L / a, the height of the ceiling is h, the height from the floor to the terminal station antenna is Hr, and the height from the floor to the base station antenna is Ht. , H = Ht−Hr, the height from the floor determined using H of the transmission / reception height difference, when the value of a is 5/4 ≦ a ≦ 5, the item number of “Table 4 ” 1, 1 <for a <5/4, No. 2-4 "table 4", 5 <for a, "table 4" represented by any one of item number 5-7, the wall a And the range on the wall surface of the wall B, and from the floor obtained using H of the mirror image transmission / reception height difference of the ceiling reflection given by H = 2h-Ht-Hr Range of height, the value of a is, for 5/4 ≦ a ≦ 5,
"Table 4" For No. 6,1 <a <5/4 of, "Table 4" No. 2-4, 5 <For a, any one of item number 5-7 in "Table 4" The range on the wall surface of the wall A and the wall B represented by the term is made of a material that absorbs radio waves or a material with a small reflection coefficient, or is covered with a panel, wallpaper, or paint made of the above materials. Characteristic wireless communication space.

When the wall corresponding to the range composed of a material that absorbs radio waves or a material with a small reflection coefficient includes a window that reflects radio waves such as shield glass, it is made of a material that absorbs radio waves or a material with a small reflection coefficient Claims: A range corresponding to the range is made of glass or the like made of a material having a low reflection coefficient that transmits radio waves, or is covered with a panel, wallpaper or paint made of a material having a low reflection coefficient that absorbs radio waves. The wireless communication space according to claim 1 .

A structure in which the wall corresponding to the range composed of a material that absorbs radio waves or a material with a small reflection coefficient is covered with a shielding curtain such as a curtain or blind made of a material with a small reflection coefficient that absorbs radio waves or a material with a small reflection coefficient The wireless communication space according to claim 1, wherein:

The wall corresponding to the range constituted by a material absorbing radio waves or a material having a small reflection coefficient is made of a material having a small reflection coefficient or a material having a small reflection coefficient for absorbing radio waves, or a panel made of the above material, The wireless communication space according to claim 1 , wherein the wireless communication space is configured to be covered with furniture such as a library, a fence, and a partition covered with wallpaper or paint.