JP3610911B2

JP3610911B2 - Transmission power control method and transmission power control apparatus

Info

Publication number: JP3610911B2
Application number: JP2001020674A
Authority: JP
Inventors: 智馬場
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2001-01-29
Filing date: 2001-01-29
Publication date: 2005-01-19
Anticipated expiration: 2021-01-29
Also published as: JP2002223168A

Description

【０００１】
【発明の属する技術分野】
本発明は、無線通信方式における送信電力制御方法及び送信電力制御装置に関し、特に自局および相手局が双方の送信電力および受信電力を監視することにより、伝播路障害か機器故障かを判定し、受信電力の低下が生じた際、機器故障の場合は送信電力を強制的に既定送信電力に制御する送信電力制御方法及び送信電力制御装置に関する。
【０００２】
【従来の技術】
従来、この種の送信電力制御装置では、自局は相手局で電波を受信したときの電波伝播状態、例えば、マイクロ波帯の電波伝播におけるフェージング等の気象条件による受信電力の低下に対応して送信電力を制御することによって、相手局での受信電力の低下を阻止し、信号品質の劣化を回避することが行われている。
【０００３】
また近年では、降雨や選択性フェージングが発生したときに、送信電力を制御することにより、空間の伝播ロスによる信号品質の劣化を防止するだけでなく、降雨やフェージングが発生していない定常時には、信号品質が劣化しない程度に送信電力を低下することにより、隣接する他の伝送信号への干渉低減あるいは送信部の非線形歪みによる信号品質の劣化防止を行うなど、回線品質の向上と低消費電力化とを実現する送信電力制御が求められている。
【０００４】
この送信電力制御を行う方式は、大きく分けて２通りある。１つは、自局の受信電力に基づいて送信電力を制御する方法であり、他の１つは、相手局から送信された受信電力情報に基づいて送信電力を制御する方法である。両方式ともに、受信系が所要ゲインに対して低下するような故障が生じた場合、伝播ロスが増大したとして、送信電力を増大することにより、隣接する他伝送信号への干渉および送信電力増幅器の非線形歪みによる信号品質の劣化を生じるという問題がある。さらに、後者の相手局から送信された受信電力情報に基づき送信電力を制御する方式は、相手局の送信部が正常に制御されないために自局の受信電界が低下したままで、信号品質の劣化が生じるという問題があった。
【０００５】
【発明が解決しようとする課題】
上述した従来の送信電力制御装置は、受信系が所要ゲインに対して低下するような故障が生じた場合には、伝播ロスが増大したとして、送信電力を増大することにより、隣接する他伝送信号への干渉および送信電力増幅器の非線形歪みによる信号品質の劣化を生じるという欠点がある。
【０００６】
さらに、相手局から送信された受信電力情報に基づき自局の送信電力を制御する方式の場合には、相手局の送信部が正常に制御されないために自局の受信電界が低下したままで、信号品質の劣化が生じるという欠点を有している。
【０００７】
本発明の目的は、このような従来の欠点を除去するため、自局および相手局で送信電力と受信電力とをそれぞれ監視することにより、伝播路障害か機器故障かを判定し、受信電力の低下が生じた際、機器故障の場合は送信電力を強制的に既定の送信電力に制御する送信電力制御装置を提供することにある。
【０００９】
【課題を解決するための手段】
本発明の送信電力制御方法は、相手局の受信電力に基づき自局の送信電力を制御する送信電力制御方法であって、自局および相手局の送信電力と受信電力とを監視し、監視情報により双方向の伝播ロスを含む減衰量をそれぞれ算出してレベル差を求め、前記減衰量のそれぞれの変化速度または前記レベル差に基づいて伝播路障害か機器故障かを判定し、相手局の受信電力の低下が生じたとき、前記レベル差が小さい伝播路障害の場合には、自局が相手局の受信電力の低下に応じて送信電力を増大し、前記レベル差が大きい機器故障の場合には、自局および相手局が送信電力を強制的に既定された送信電力に固定する制御を行うことを特徴としている。
【００１０】
また、本発明の送信電力制御方法は、自局の受信電力に基づき自局の送信電力を制御する送信電力制御方法であって、自局および相手局の送信電力と受信電力とを監視し、監視情報により双方向の伝播ロスを含む減衰量をそれぞれ算出してレベル差を求め、前記減衰量のそれぞれの変化速度または前記レベル差に基づいて伝播路障害か機器故障かを判定し、自局の受信電力の低下が生じたとき、前記レベル差が小さい伝播路障害の場合には、自局が自局の送信電力を既定された時間の間固定した後に自局の受信電力の低下に応じて段階的に増大し、前記レベル差が大きい機器故障の場合には、自局および相手局が送信電力を強制的に既定された送信電力に固定する制御を行うことを特徴としている。
【００１１】
また、本発明の送信電力制御装置は、自局または相手局の受信電力に基づき送信電力を制御する送信電力制御装置であって、相手局の送信電力情報および受信電力情報を含むＡＴＰＣ制御信号を受信するとともに自局の受信電力モニタ信号を出力する受信部と、前記受信部出力を復調する復調部と、前記自局の受信電力モニタ信号から変換した自局の受信電力情報または前記復調部出力から取り出した前記相手局の受信電力情報に基づき自局または相手局の受信電力が低下したときに送信電力を増大する送信電力制御信号を出力する制御部と、前記制御部で生成された自局の送信電力情報および前記自局の受信電力情報を取り込みＡＴＰＣ制御信号を出力する変調部と、前記変調部出力を送信信号に変換したのち前記送信電力制御信号に基づき増幅して出力する送信部とを有し、前記制御部が前記相手局の送信電力情報および受信電力情報と前記自局の送信電力情報および前記自局の受信電力情報とにより伝播路障害か機器故障かを判定し、自局または相手局の受信電力の低下が生じたときに、伝播路障害の場合には、自局または相手局の受信電力の低下に応じて送信電力を増大する前記送信電力制御信号を出力し、機器故障の場合には、既定された送信電力に固定する前記送信電力制御信号を前記送信部へ出力するとともに相手局へ通知する強制制御信号を出力することを特徴としている。
【００１２】
また、前記制御部は、前記相手局の送信電力情報および受信電力情報と前記自局の送信電力情報および前記自局の受信電力情報とにより、双方向の伝播ロスを含む減衰量をそれぞれ算出してレベル差を求め、前記レベル差が既定値の範囲内のときは伝播路障害を、前記レベル差が既定値の範囲を越えたときは機器故障を判定することを特徴としている。
【００１３】
また、前記制御部は、前記相手局の送信電力情報および受信電力情報と前記自局の送信電力情報および前記自局の受信電力情報とにより、双方向の伝播ロスを含む減衰量を算出してそれぞれの時間的変化を監視し、前記時間的変化が遅いときは伝播路障害を、早いときは機器故障を判定することを特徴としている。
【００１４】
また、前記制御部は、相手局の受信電力の低下が生じたとき、伝播路障害の場合には、前記送信部に送信電力を増大する前記送信電力制御信号を出力し、機器故障の場合には、前記送信部に対して既定された送信電力に固定する前記送信電力制御信号を出力するとともに、前記変調部に対して相手局へ通知する強制制御信号を同時に出力することを特徴としている。
【００１５】
また、前記制御部は、自局の受信電力の低下が生じたとき、伝播路障害の場合には、自局が自局の送信電力を予め設定された時間の間固定した後に自局の受信電力の低下に応じて段階的に増大する前記送信電力制御信号を出力し、機器故障の場合には、前記送信部に対して既定された送信電力に固定する前記送信電力制御信号を出力するとともに、前記変調部に対して相手局へ通知する強制制御信号を同時に出力することを特徴としている。
【００１６】
【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。図１は、本発明の送信電力制御装置の一つの実施の形態を示すブロック図である。
【００１７】
図１に示す本実施の形態は、Ａ局では変調部（ＭＯＤ−ＥＮＣ）１０ａ、送信部（ＴＸ）２０ａ、受信部（ＲＸ）３０ａ、復調部（ＤＥＭ−ＤＥＣ）４０ａおよび制御部（ＡＴＰＣＣＯＮＴ）５０ａより構成され、Ｂ局では変調部（ＭＯＤ−ＥＮＣ）１０ｂ、送信部（ＴＸ）２０ｂ、受信部（ＲＸ）３０ｂ、復調部（ＤＥＭ−ＤＥＣ）４０ｂおよび制御部（ＡＴＰＣＣＯＮＴ）５０ｂより構成されている。また、６０ａはＡ局側アンテナ、６０ｂはＢ局側アンテナである。
【００１８】
次に、本実施の形態の送信電力制御装置の動作を図１および図２を参照して詳細に説明する。図２は、図１に示す制御部の構成を示すブロック図である。図１において、Ａ局とＢ局とは同一構成であり、Ａ局を自局、Ｂ局を相手局として以下の説明を行う。
【００１９】
図１によると、まず、Ｂ局はＡ局からの受信電力を監視し、受信部３０ｂから出力された受信電力モニタ電圧（ＲＰＷＲＭＯＮ−Ｂ）を制御部５０ｂで受信電力情報（ＲＰＷＲＤＡＴＡ−Ｂ）に変換する。また、Ａ局あるいはＢ局の受信電力に基づいて送信電力情報（ＴＰＷＲＤＡＴＡ−Ｂ）を制御部５０ｂで生成し、送信電力制御信号（ＴＰＷＲＣＯＮＴ−Ｂ）に変換して送信電力を制御する。そして、送信電力情報（ＴＰＷＲＤＡＴＡ−Ｂ）および受信電力情報（ＲＰＷＲＤＡＴＡ−Ｂ）を変調部１０ｂで伝送データに変換し、ＡＴＰＣ制御信号として送信部２０ｂを介してＡ局へ送信する。
【００２０】
Ａ局は、Ｂ局から受信したＡＴＰＣ制御信号を復調部４０ａで復調した後、制御部５０ａで送信電力情報（ＴＰＷＲＤＡＴＡ−Ｂ）および受信電力情報（ＲＰＷＲＤＡＴＡ−Ｂ）を取り出す。また、制御部５０ａでは受信部３０ａから出力された受信電力モニタ電圧（ＲＰＷＲＭＯＮ−Ａ）を受信電力情報（ＲＰＷＲＤＡＴＡ−Ａ）に変換するとともに、Ａ局またはＢ局の受信電力に基づいて送信電力情報（ＴＰＷＲＤＡＴＡ−Ａ）を生成し、受信電力の低下に応じて送信電力を増大する送信電力制御信号（ＴＰＷＲＣＯＮＴ−Ａ）を出力し、送信部２０ａの、例えば可変減衰器に供給して送信電力制御を行う。
【００２１】
また、Ａ局は自局の送信電力情報（ＴＰＷＲＤＡＴＡ−Ａ）および受信電力情報（ＲＰＷＲＤＡＴＡ−Ａ）を変調部１０ａで伝送データに変換し、ＡＴＰＣ制御信号として送信部２０ａを介してＢ局へ送信する。
【００２２】
このようにして、Ａ局およびＢ局は相互の受信電力情報に基づいて、それぞれに送信電力制御を行うことができる。
【００２３】
次に、制御部の構成に基づいて送信電力制御の動作を説明する。
【００２４】
図２によると、制御部５０ａはＣＯＮＶ５１ａ、ＤＡＴＡＣＯＮＶ５２ａ、ＤＡＴＡＣＯＮＶ５３ａ、ＣＯＭＰ＆ＴＩＭＥＲ（比較器）５４ａ、ＴＰＷＲＣＯＮＴ（送信電力制御器）５５ａおよびＣＯＮＶ５６ａより構成され、復調部４０ａを介して取り出したＢ局の受信電力情報（ＲＰＷＲＤＡＴＡ−Ｂ）に基づいてＡ局の送信電力を制御する。
【００２５】
ＣＯＮＶ５１ａは、Ｂ局からの受信電力を監視する受信部３０ａから出力されたＡ局での受信電力モニタ電圧（ＲＰＷＲＭＯＮ−Ａ）より受信電力情報（ＲＰＷＲＤＡＴＡ−Ａ）に変換して出力する。
【００２６】
ＤＡＴＡＣＯＮＶ５２ａは、復調部４０ａから出力されたＡＴＰＣ制御信号より、Ｂ局の送信電力情報（ＴＰＷＲＤＡＴＡ−Ｂ）と受信電力情報（ＲＰＷＲＤＡＴＡ−Ｂ）とを取り出して出力する。
【００２７】
ＤＡＴＡＣＯＮＶ５３ａは、Ａ局の送信電力情報（ＴＰＷＲＤＡＴＡ−Ａ）と受信電力情報（ＲＰＷＲＤＡＴＡ−Ａ）とをデータ変換して、変調部１０ａへ出力する。
【００２８】
ＣＯＭＰ＆ＴＩＭＥＲ５４ａは、ＤＡＴＡＣＯＮＶ５２ａから出力されたＢ局の送信電力情報（ＴＰＷＲＤＡＴＡ−Ｂ）および受信電力情報（ＲＰＷＲＤＡＴＡ−Ｂ）と、ＣＯＮＶ５１ａから出力されたＡ局の受信電力情報（ＲＰＷＲＤＡＴＡ−Ａ）およびＴＰＷＲＣＯＮＴ５５ａから出力されたＡ局の送信電力情報（ＴＰＷＲＤＡＴＡ−Ａ）とを入力し、送信方向（Ａ局→Ｂ局）の伝播ロスを含む減衰量（｜ＴＰＷＲＤＡＴＡ−Ａ｜−｜ＲＰＷＲＤＡＴＡ−Ｂ｜）と、受信方向（Ａ局←Ｂ局）の伝播ロスを含む減衰量（｜ＴＰＷＲＤＡＴＡ−Ｂ｜−｜ＲＰＷＲＤＡＴＡ−Ａ｜）とをそれぞれ算出し２つの減衰量からレベル差を求める。このレベル差が既定値の範囲を越えて既定時間以上に渡り生じた場合、Ａ局またはＢ局の送信部２０ａ、２０ｂあるいは受信部３０ａ、３０ｂの故障と判断し、送信電力を強制的に既定された送信電力に固定する強制制御信号（ＣＯＮＴＳＩＧ−Ａ）を送出する。この強制制御信号（ＣＯＮＴＳＩＧ−Ａ）は、Ａ局の送信電力制御信号（ＴＰＷＲＣＯＮＴ−Ａ）を既定された送信電力に強制設定するとともに、ＤＡＴＡＣＯＮＶ５３ａに対してＢ局へ通知するため出力される。Ｂ局は、この強制制御信号（ＣＯＮＴＳＩＧ−Ａ）（図２に示すＣＯＮＴＳＩＧ−Ｂに相当する。）を検出すると、直ちに送信電力制御信号（ＴＰＷＲＣＯＮＴ−Ｂ）を既定された送信電力に強制設定する。
【００２９】
ＴＰＷＲＣＯＮＴ５５ａは、ＣＯＮＶ５２ａから入力されたＢ局の受信電力情報（ＲＰＷＲＤＡＴＡ−Ｂ）が、既定のしきい値より低下したとき、送信電力を現送信電力から増大する送信電力情報（ＴＰＷＲＤＡＴＡ−Ａ）を出力する。この制御は、Ｂ局の受信電力に応じて送信部２０ａの送信電力を最大設定送信電力まで１ステップ、例えば１ｄＢ毎に増大し、また、伝播ロスが減少してＢ局の受信電力が増大し、受信電力が既定のしきい値に達するとき最小電力値になるよう、送信部２０ａの送信電力を１ステップ毎に下げる制御を行う。
【００３０】
ＣＯＮＶ５６ａは、ＴＰＷＲＣＯＮＴ５５ａから出力された送信電力情報（ＴＰＷＲＤＡＴＡ−Ａ）を送信電力制御信号（ＴＰＷＲＣＯＮＴ−Ａ）に変換し、送信部２０ａの例えば可変減衰器の制御を行うことで、送信電力を制御する。
【００３１】
したがって、制御部５０ａは、同じ空間を伝送しているＡ局とＢ局との間の双方向の伝送路状態を比較して、伝播路障害か機器故障かを判定することにより、降雨などによりＢ局の受信電力が低下した場合、Ｂ局の受信電力の低下に応じてＡ局の送信電力を増大することにより、サーマルノイズの影響による信号品質の劣化を防ぐことができる。
【００３２】
また、降雨やフェージングが無い定常状態で、機器故障により受信電力が低下した場合には、Ａ局およびＢ局が送信電力を強制的に既定された送信電力、例えば最小送信電力に固定することにより、隣接する他伝送信号への干渉および送信電力増幅器の非線形歪みによる信号品質の劣化を防ぐことができる。
【００３３】
次に、本実施の形態の送信電力の制御をタイムチャートを用いて説明する。図３は、降雨による受信電力の低下に対する送信電力の制御を示すタイムチャートである。図４は、選択性フェージングによる受信電力の低下に対する送信電力の制御を示すタイムチャートである。図５は、Ａ局の受信部故障による受信電力の低下に対する送信電力の制御を示すタイムチャートである。
【００３４】
なお、図３、図４および図５において、伝播ロスは伝送路の伝播ロスを含む減衰量、すなわち送信電力情報と受信電力情報との差であり、また、わかりやすくするため正常時の受信電力を基準として、減衰量の増大方向を受信電力の低下方向に合わせて示している。
【００３５】
まず、降雨による相手局の受信電力の低下に対する自局の送信電力の制御について説明する。図３（ａ）は、伝播ロスに伴うＢ局の受信電力に対するＡ局の送信電力制御を示すタイムチャートである。図３（ｂ）は、伝播ロスに伴うＡ局の受信電力に対するＢ局の送信電力制御を示すタイムチャートである。図３（ｃ）は、ＣＯＭＰ（比較）出力を示すタイムチャートである。
【００３６】
降雨の場合は、図３（ａ）および（ｂ）に示すように、双方向の伝播ロスの増大に伴って、Ａ局、Ｂ局ともに受信電力が低下していく。そして、Ａ局では、Ｂ局の受信電力が既定のしきい値以下となった時、Ｂ局の受信電力の低下に応じてＡ局の送信電力を、例えば１ｄＢ毎に増大する制御を行う。また、Ｂ局でも同様に、Ａ局の受信電力が既定のしきい値以下となった時、Ａ局の受信電力の低下に応じてＢ局の送信電力を、同様に１ｄＢ毎に増大する制御を行う。
【００３７】
ここで、ＣＯＭＰ＆ＴＩＭＥＲ５４ａは、送信方向（Ａ局→Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ａ｜−｜ＲＰＷＲＤＡＴＡ−Ｂ｜）と、受信方向（Ａ局←Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ｂ｜−｜ＲＰＷＲＤＡＴＡ−Ａ｜）とをそれぞれ算出して２つのレベル差を求める。降雨による伝播ロスは、双方向でレベル差がほとんどないため、図３（Ｃ）に示すように、レベル差（ＣＯＭＰ出力）は、ほぼ０、すなわち０ｄＢとなる。これより、ＣＯＭＰ＆ＴＩＭＥＲ５４ａは正常動作（ＮＯＲＭ）を示す制御信号を出力する。この制御信号に基づき、送信電力制御が正常に行なわれる。すなわち、Ａ局およびＢ局は、互いの受信電力の低下に応じて送信電力を最大値に至るまで増大する制御を行う。また、伝播ロスが減少し、受信電力が増大に転じたときには、互いの受信電力の増大に応じて送信電力を低下する制御を行う。
【００３８】
次に、選択性フェージングによる相手局の受信電力の低下に対する自局の送信電力の制御について説明する。図４（ａ）は、伝播ロスに伴うＢ局の受信電力に対するＡ局の送信電力制御を示すタイムチャートである。図４（ｂ）は、伝播ロスに伴うＡ局の受信電力に対するＢ局の送信電力制御を示すタイムチャートである。図４（ｃ）は、ＣＯＭＰ（比較）出力を示すタイムチャートである。
【００３９】
Ｂ局の受信電力は、図４（ａ）に示すように、選択性フェージングの影響が小さく、多少の伝播ロスがあるものの既定のしきい値以下にはならない。したがって、Ａ局の送信電力は既定された送信電力、例えば最小送信電力に制御されたままである。
【００４０】
一方、Ａ局の受信電力は、図４（ｂ）に示すように、選択性フェージングの影響が大きく、受信電力が低下してしきい値以下となり、Ｂ局の送信電力制御が行われている。
【００４１】
ここで、ＣＯＭＰ＆ＴＩＭＥＲ５４ａは、送信方向（Ａ局→Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ａ｜−｜ＲＰＷＲＤＡＴＡ−Ｂ｜）と、受信方向（Ａ局←Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ｂ｜−｜ＲＰＷＲＤＡＴＡ−Ａ｜）とをそれぞれ算出して２つのレベル差を求める。選択性フェージングの影響により、図４（ｃ）に示すように、レベル差（ＣＯＭＰ出力）は大きくなり、機器故障と判定する。
【００４２】
しかし、選択性フェージングは、一般に一時的であることから、任意の継続時間（ＴＩＭＥＲ区間）を設定しておくことにより、ＴＩＭＥＲ区間以内に選択性フェージングによるＡＬＭ検出区間が止まる場合には、ＣＯＭＰ＆ＴＩＭＥＲ５４ａは、機器故障と切り分けて正常動作（ＮＯＲＭ）を示す制御信号を出力することができる。
【００４３】
次に、自局の受信部故障による相手局の受信電力の低下に対する自局の送信電力の制御について説明する。図５（ａ）は、伝播ロスに伴うＢ局の受信電力に対するＡ局の送信電力制御を示すタイムチャートである。図５（ｂ）は、伝播ロスに伴うＡ局の受信電力に対するＢ局の送信電力制御を示すタイムチャートである。図３（ｃ）は、ＣＯＭＰ（比較）出力を示すタイムチャートである。
【００４４】
まず、Ｂ局の受信電力は、図５（ａ）に示すように、降雨やフェージングによる減衰がなく安定し、既定のしきい値以下にならず、Ａ局の送信電力は最小送信電力に制御されている。
【００４５】
次に、受信部３０ａが故障したＡ局は、図５（ｂ）に示すように、受信電力が低下し、Ｂ局の受信電力に比べて低い値を示す。このとき、Ａ局の受信電力が既定のしきい値以下となるため、Ｂ局が送信電力を増大する制御を行う。
【００４６】
ここで、ＣＯＭＰ＆ＴＩＭＥＲ５４ａは、送信方向（Ａ局→Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ａ｜−｜ＲＰＷＲＤＡＴＡ−Ｂ｜）と、受信方向（Ａ局←Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ｂ｜−｜ＲＰＷＲＤＡＴＡ−Ａ｜）とをそれぞれ算出して２つのレベル差を求めたとき、レベル差（ＣＯＭＰ出力）は明らかに大きくなるため、機器故障と判定する。また、機器故障の場合はフェージングと異なり一時的な場合が少なく、任意の継続時間（ＴＩＭＥＲ区間）を超えて起こる。この判定結果に基づき、ＣＯＭＰ＆ＴＩＭＥＲ５４ａは、送信電力を既定された送信電力、例えば最小送信電力に制御する強制制御信号（ＣＯＮＴＳＩＧ−Ａ）をＴＰＷＲＣＯＮＴ５５ａへ出力するとともに、Ｂ局の送信電力を最小送信電力に制御するためＤＡＴＡＣＯＮＶ５３ａへも出力する。したがって、Ａ局およびＢ局は、機器故障が検出されたときに出力される強制制御信号（ＣＯＮＴＳＩＧ−Ａ）により、送信電力を既定された送信電力に制御することができる。
【００４７】
以上の説明では、Ａ局の送信電力制御は、Ｂ局の受信電力に基づき行う場合であるが、Ａ局が自局の受信電力に基づき送信電力の制御を行うことも可能である。図６は、Ａ局が自局の受信電力に基づいて送信電力制御を行う場合の制御部のブロック図である。
【００４８】
図６によると、制御部５０ａのＣＯＭＰ＆ＴＩＭＥＲ５４ａが、送信方向（Ａ局→Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ａ｜−｜ＲＰＷＲＤＡＴＡ−Ｂ｜）と、受信方向（Ａ局←Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ｂ｜−｜ＲＰＷＲＤＡＴＡ−Ａ｜）とを比較する点は同じであるが、Ａ局の送信電力情報（ＴＰＷＲＤＡＴＡ−Ａ）をＡ局の受信電力情報（ＲＰＷＲＤＡＴＡ−Ａ）から生成し、自局の受信電力の低下に応じて送信電力を段階的に増大する点が異なる。
【００４９】
通常、Ａ局、Ｂ局間の送受信伝送は、同一周波数帯でかつ一定間隔を隔てた複数の周波数が使用されている。これにより、降雨による伝播ロスは周波数によらず相関があるものとし、Ａ局の送信電力を自局の受信電力に基づいて制御する方法が採用されている場合がある。この利点としては、構成が簡略化され早いフェージングに追従できることが挙げられる。しかし、Ａ局の送信電力を自局の受信電力に基づいて制御するだけでは、Ｂ局の送信電力が正常に制御されず、Ａ局の受信電界が低下し、信号品質の劣化が生じることがある。
【００５０】
図７は、Ａ局が自局の受信電力に基づいて送信電力制御を行う場合のタイムチャートである。図７（ａ）は、伝播ロスに伴うＡ局の受信電力に対するＡ局の送信電力制御を示すタイムチャートである。図７（ｂ）は、伝播ロスに伴うＢ局の受信電力に対するＢ局の送信電力制御を示すタイムチャートである。
【００５１】
図７によると、降雨などにより伝播ロスが増大し、Ａ局およびＢ局の受信電界がともに低下していく。そして、Ａ局は受信電力が既定されたしきい値以下になったときから、送信電力を最小送信電力から１ｄＢ単位で上げていく。Ｂ局は、降雨により受信電力が低下するが、Ａ局が送信電力を増大したため、既定されたしきい値以下にならないため、送信電力を最小電力に制御したままの状態となる。さらに伝播ロスが増大しても、同様の動作が繰り返されるため、Ａ局の送信電力が制御できる最大電力まで、Ｂ局の送信電力は最小電力に制御されたままとなる。この結果、Ａ局の受信電界が低下し、サーマルノイズの影響による信号品質の劣化が生じる。
【００５２】
ここで、ＣＯＭＰ＆ＴＩＭＥＲ５４ａは、送信方向（Ａ局→Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ａ｜−｜ＲＰＷＲＤＡＴＡ−Ｂ｜）と、受信方向（Ａ局←Ｂ局）の伝播ロス（｜ＴＰＷＲＤＡＴＡ−Ｂ｜−｜ＲＰＷＲＤＡＴＡ−Ａ｜）とをそれぞれ算出して２つのレベル差を求め、Ａ局が自局の受信電力の低下を検出したとき、レベル差が小さい伝播路障害の場合には、自局の送信電力を既定の時間固定した後に受信電力の低下に応じて段階的に増大する制御を行う。
【００５３】
この制御は、Ａ局が送信電力を増大するときに既定の時間固定した後上げ幅を段階的に行うことにより、Ｂ局が送信電力の上げ幅を段階的に増大する制御を行った後、不足分をＡ局が送信電力を増大するため、一方だけが送信電力を増大することを防ぐことができる。さらに伝播ロスが増大した場合も、同様の動作を行い、Ａ局のみが送信電力を増大することがなくバランスのとれた制御ができる。したがって、フェージングの変化に追従しながら、降雨によるＡ局の受信電力の低下を防止でき、Ａ局、Ｂ局いずれにおいても信号品質の劣化を防ぐことができる。一方、レベル差が大きい機器故障の場合には、前述と同様に、Ａ局およびＢ局が送信電力を強制的に既定された送信電力に固定する制御を行う。
【００５４】
また、制御部内のＣＯＭＰ＆ＴＩＭＥＲをＣＰＵにすることができる。図８は、図１に示す制御部にＣＰＵを用いた構成を示すブロック図である。
【００５５】
図８によると、ＣＰＵ５７ａは、双方向の伝播ロスの時間的変化を監視することにより、伝播路障害か機器故障かを早く見極めることができる。特に選択性フェージングの場合、伝播路の状態による受信電力の低下がある周波数、すなわち共振周波数（以降“ノッチ”と呼ぶ）で現れることがある。その際、対向間で通信している周波数に長時間にわたりノッチが入った場合、ＣＯＭＰ＆ＴＩＭＥＲ５４ａではアラーム検出時間（ＡＬＭ検出区間）が長く設定されていると機器故障と判定してしまう。しかし、ＣＰＵ５７ａでは、伝播ロスの時間的変化を監視することにより、ゆっくりと減衰していく選択性フェージングとある時突然受信電力が低下する機器故障の検出とを、短時間で判定することができる。
【００５６】
【発明の効果】
以上説明したように、本発明の送信電力制御方法及び送信電力制御装置によれば、自局および相手局で送信電力と受信電力とをそれぞれ監視して、伝播路障害か機器故障かを判定し、受信電力の低下が生じた際、機器故障の場合は送信電力を強制的に既定の送信電力に制御することにより、機器故障による他回線への干渉を防ぐことができるという効果がある。
【図面の簡単な説明】
【図１】本発明の送信電力制御装置の一つの実施の形態を示すブロック図である。
【図２】図１に示す制御部の構成を示すブロック図である。
【図３】降雨による受信電力の低下に対する送信電力の制御を示すタイムチャートである。
【図４】選択性フェージングによる受信電力の低下に対する送信電力の制御を示すタイムチャートである。
【図５】Ａ局の受信部故障による受信電力の低下に対する送信電力の制御を示すタイムチャートである。
【図６】Ａ局が自局の受信電力に基づいて送信電力制御を行う場合の制御部のブロック図である。
【図７】Ａ局が自局の受信電力に基づいて送信電力制御を行う場合のタイムチャートである。
【図８】図１に示す制御部にＣＰＵを用いた構成を示すブロック図である。
【符号の説明】
１０ａ、１０ｂ変調部（ＭＯＤ−ＥＮＣ）
２０ａ、２０ｂ送信部（ＴＸ）
３０ａ、３０ｂ受信部（ＲＸ）
４０ａ、４０ｂ復調部（ＤＥＭ−ＤＥＣ）
５０ａ、５０ｂ制御部（ＡＴＰＣＣＯＮＴ）
６０ａ、６０ｂアンテナ
５１ａＣＯＮＶ
５２ａＤＡＴＡＣＯＮＶ
５３ａＤＡＴＡＣＯＮＶ
５４ａＣＯＭＰ＆ＴＩＭＥＲ
５５ａＴＰＷＲＣＯＮＴ
５６ａＣＯＮＶ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission power control method and a transmission power control apparatus in a wireless communication system, and in particular, determines whether a propagation path failure or a device failure by monitoring the transmission power and reception power of both the local station and the partner station, The present invention relates to a transmission power control method and a transmission power control apparatus for forcibly controlling transmission power to a predetermined transmission power in the case of equipment failure when reception power is reduced.
[0002]
[Prior art]
Conventionally, in this type of transmission power control device, the local station responds to a decrease in received power due to weather conditions such as fading in radio wave propagation in the microwave band when the local station receives radio waves at the other station, for example. By controlling the transmission power, it is possible to prevent a decrease in received power at the partner station and to avoid signal quality degradation.
[0003]
In recent years, when rain or selective fading occurs, controlling transmission power not only prevents signal quality deterioration due to space propagation loss, but also during steady periods when no rain or fading occurs. By reducing the transmission power to such an extent that the signal quality does not deteriorate, the line quality is improved and the power consumption is reduced, such as reducing interference with other adjacent transmission signals or preventing signal quality deterioration due to nonlinear distortion of the transmitter. There is a demand for transmission power control that realizes
[0004]
There are roughly two methods for performing the transmission power control. One is a method for controlling the transmission power based on the received power of the own station, and the other is a method for controlling the transmission power based on the received power information transmitted from the partner station. In both systems, when a failure occurs in which the receiving system decreases with respect to the required gain, it is assumed that the propagation loss has increased. By increasing the transmission power, interference with other adjacent transmission signals and the transmission power amplifier There is a problem that signal quality is deteriorated due to nonlinear distortion. Furthermore, the method of controlling the transmission power based on the reception power information transmitted from the latter partner station is not effective in controlling the transmission unit of the partner station, so that the reception electric field of the own station is reduced and the signal quality is deteriorated. There was a problem that occurred.
[0005]
[Problems to be solved by the invention]
In the conventional transmission power control device described above, when a failure occurs such that the reception system decreases with respect to the required gain, it is assumed that the propagation loss has increased, and by increasing the transmission power, the adjacent other transmission signal Signal quality degradation due to interference and non-linear distortion of the transmit power amplifier.
[0006]
Furthermore, in the case of a method for controlling the transmission power of the own station based on the received power information transmitted from the counterpart station, the reception field of the own station remains lowered because the transmission unit of the counterpart station is not normally controlled. It has the disadvantage that signal quality is degraded.
[0007]
An object of the present invention is to determine whether a propagation path failure or a device failure by monitoring transmission power and reception power at each of the local station and the partner station in order to eliminate such conventional drawbacks. An object of the present invention is to provide a transmission power control apparatus for forcibly controlling transmission power to a predetermined transmission power in the case of a device failure when a reduction occurs.
[0009]
[Means for Solving the Problems]
Book The transmission power control method of the invention is a transmission power control method for controlling the transmission power of the local station based on the reception power of the counterpart station, and monitors the transmission power and the reception power of the local station and the counterpart station, Calculate the attenuation including bi-directional propagation loss to determine the level difference, determine the propagation speed failure or equipment failure based on the rate of change of each attenuation or the level difference, and receive power of the partner station In the case of a propagation path failure where the level difference is small, the local station increases the transmission power in response to a decrease in the reception power of the partner station, and in the case of a device failure where the level difference is large The self station and the partner station perform control to forcibly fix the transmission power to a predetermined transmission power.
[0010]
Further, the transmission power control method of the present invention is a transmission power control method for controlling the transmission power of the local station based on the reception power of the local station, monitoring the transmission power and the reception power of the local station and the partner station, Attenuation amount including bidirectional propagation loss is calculated by monitoring information to obtain a level difference, and it is determined whether a propagation path failure or a device failure based on the speed of change of each attenuation amount or the level difference. In the case of a propagation path failure where the level difference is small, The transmission power of your station After fixing for a predetermined time Self In the case of a device failure that increases stepwise in response to a decrease in received power of the station and the level difference is large, the local station and the other station perform control to forcibly fix the transmission power to the predetermined transmission power. It is characterized by that.
[0011]
The transmission power control apparatus of the present invention is a transmission power control apparatus that controls transmission power based on the reception power of the local station or the counterpart station, and that transmits an ATPC control signal including transmission power information and reception power information of the counterpart station. A receiver that receives and outputs the received power monitor signal of the own station; a demodulator that demodulates the output of the receiver; and received power information of the own station converted from the received power monitor signal of the own station or the output of the demodulator A control unit that outputs a transmission power control signal that increases transmission power when the reception power of the local station or the counterpart station decreases based on the reception power information of the counterpart station extracted from the local station, and the local station generated by the control unit Based on the transmission power control signal after converting the modulation unit output into a transmission signal, and a modulation unit that takes in the transmission power information and the reception power information of the local station and outputs an ATPC control signal. A transmission unit that amplifies and outputs, and the control unit determines whether or not a propagation path failure is caused by the transmission power information and reception power information of the counterpart station, the transmission power information of the local station, and the reception power information of the local station. In the case of a propagation path failure, when the reception power of the local station or the partner station decreases, the transmission power increases according to the decrease of the reception power of the local station or the partner station. A power control signal is output, and in the case of equipment failure, the transmission power control signal that is fixed to a predetermined transmission power is output to the transmitter and a forced control signal that is notified to the other station is output. Yes.
[0012]
Further, the control unit calculates an attenuation amount including a bidirectional propagation loss based on the transmission power information and reception power information of the counterpart station and the transmission power information of the local station and the reception power information of the local station. A level difference is obtained, and when the level difference is within a predetermined range, a propagation path failure is determined, and when the level difference exceeds a predetermined value range, a device failure is determined.
[0013]
In addition, the control unit calculates an attenuation amount including a bidirectional propagation loss based on the transmission power information and reception power information of the counterpart station, the transmission power information of the local station, and the reception power information of the local station. Each time change is monitored, and when the time change is slow, a propagation path failure is judged, and when it is early, a device failure is judged.
[0014]
In addition, the control unit outputs the transmission power control signal for increasing the transmission power to the transmission unit in the case of a propagation path failure when a decrease in the reception power of the counterpart station occurs, and in the case of a device failure Is characterized by outputting the transmission power control signal fixed to a predetermined transmission power to the transmission unit and simultaneously outputting a compulsory control signal for notifying the other station to the modulation unit.
[0015]
In addition, when the reception power of the local station is reduced, the control unit The transmission power of your station After fixing for a preset time Self The transmission power control signal that increases stepwise in response to a decrease in the reception power of the station is output, and in the case of equipment failure, the transmission power control signal that is fixed to the transmission power that is predetermined for the transmission unit In addition to outputting, a compulsory control signal for notifying the other station of the modulation unit is simultaneously output.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a transmission power control apparatus according to the present invention.
[0017]
In the present embodiment shown in FIG. 1, in the A station, a modulation unit (MOD-ENC) 10a, a transmission unit (TX) 20a, a reception unit (RX) 30a, a demodulation unit (DEM-DEC) 40a, and a control unit (ATPC CONT) ) 50a, and the B station includes a modulation unit (MOD-ENC) 10b, a transmission unit (TX) 20b, a reception unit (RX) 30b, a demodulation unit (DEM-DEC) 40b, and a control unit (ATPC CONT) 50b. Has been. 60a is an A station side antenna, and 60b is a B station side antenna.
[0018]
Next, the operation of the transmission power control apparatus according to the present embodiment will be described in detail with reference to FIG. 1 and FIG. FIG. 2 is a block diagram showing a configuration of the control unit shown in FIG. In FIG. 1, the A station and the B station have the same configuration, and the following description will be made with the A station as the own station and the B station as the partner station.
[0019]
According to FIG. 1, first, the B station monitors the received power from the A station, and the received power monitor voltage (RPWR MON-B) output from the receiving unit 30b is received by the control unit 50b in the received power information (RPWR DATA-B). ). Further, the transmission power information (TPWR DATA-B) is generated by the control unit 50b based on the reception power of the A station or the B station, and is converted into a transmission power control signal (TPWR CONT-B) to control the transmission power. Then, the transmission power information (TPWR DATA-B) and the reception power information (RPWR DATA-B) are converted into transmission data by the modulation unit 10b, and transmitted to the A station via the transmission unit 20b as an ATPC control signal.
[0020]
The A station demodulates the ATPC control signal received from the B station by the demodulator 40a, and then extracts the transmission power information (TPWR DATA-B) and the received power information (RPWR DATA-B) by the control unit 50a. In addition, the control unit 50a converts the received power monitor voltage (RPWR MON-A) output from the receiving unit 30a into received power information (RPWR DATA-A) and transmits the received power based on the received power of the A station or the B station. It generates power information (TPWR DATA-A), outputs a transmission power control signal (TPWR CONT-A) that increases transmission power in response to a decrease in received power, and supplies it to the variable attenuator of the transmitter 20a, for example. To perform transmission power control.
[0021]
Further, the A station converts its own transmission power information (TPWR DATA-A) and received power information (RPWR DATA-A) into transmission data by the modulation unit 10a, and the B station via the transmission unit 20a as an ATPC control signal. Send to.
[0022]
In this way, station A and station B can perform transmission power control on the basis of the mutual received power information.
[0023]
Next, the operation of transmission power control will be described based on the configuration of the control unit.
[0024]
According to FIG. 2, the control unit 50a is composed of CONV 51a, DATA CONV 52a, DATA CONV 53a, COMP & TIMER (comparator) 54a, TPWRCONT (transmission power controller) 55a, and CONV 56a. The transmission power of station A is controlled based on the power information (RPWR DATA-B).
[0025]
The CONV 51a converts the received power monitor voltage (RPWR MON-A) output from the receiving unit 30a that monitors the received power from the B station into received power information (RPWR DATA-A) and outputs the received power information (RPWR DATA-A).
[0026]
The DATA CONV 52a extracts and outputs transmission power information (TPWR DATA-B) and reception power information (RPWR DATA-B) of station B from the ATPC control signal output from the demodulator 40a.
[0027]
The DATA CONV 53a converts the transmission power information (TPWR DATA-A) and the reception power information (RPWR DATA-A) of the station A and outputs the data to the modulation unit 10a.
[0028]
The COMP & TIMER 54a includes transmission power information (TPWR DATA-B) and reception power information (RPWR DATA-B) of the B station output from the DATA CONV 52a, and reception power information (RPWR DATA-A) of the A station output from the CONV 51a. And the transmission power information (TPWR DATA-A) of the A station output from the TPWR CONT 55a, and the attenuation amount (| TPWR DATA-A |-| RPWR including propagation loss in the transmission direction (A station → B station) DATA-B |) and an attenuation amount (| TPWR DATA-B |-| RPWR DATA-A |) including a propagation loss in the receiving direction (A station ← B station) are respectively calculated, and the level difference from the two attenuation amounts is calculated. Ask for. When this level difference exceeds the predetermined value range and exceeds a predetermined time, it is determined that the transmitting unit 20a or 20b or the receiving unit 30a or 30b of the station A or station B is faulty, and the transmission power is forcibly determined. A forced control signal (CONT SIG-A) that fixes the transmitted power is transmitted. This compulsory control signal (CONT SIG-A) is output to forcibly set the transmission power control signal (TPWR CONT-A) of the A station to a predetermined transmission power and to notify the B station to the DATA CONV 53a. The When station B detects this forced control signal (CONT SIG-A) (corresponding to CONT SIG-B shown in FIG. 2), it immediately changes the transmission power control signal (TPWR CONT-B) to the predetermined transmission power. Force setting.
[0029]
The TPWR CONT 55a transmits the transmission power information (TPWR DATA-A) that increases the transmission power from the current transmission power when the reception power information (RPWR DATA-B) of the station B input from the CONV 52a is lower than a predetermined threshold value. ) Is output. In this control, the transmission power of the transmitting unit 20a is increased by one step, for example, every 1 dB, for example, 1 dB according to the reception power of the B station, and the propagation loss is decreased and the reception power of the B station is increased. Then, control is performed to lower the transmission power of the transmission unit 20a step by step so that the minimum power value is obtained when the reception power reaches a predetermined threshold value.
[0030]
The CONV 56a converts the transmission power information (TPWR DATA-A) output from the TPWR CONT 55a into a transmission power control signal (TPWR CONT-A), and controls the variable attenuator of the transmission unit 20a, for example, thereby transmitting power. To control.
[0031]
Therefore, the control unit 50a compares the two-way transmission path state between the A station and the B station transmitting the same space, and determines whether it is a propagation path failure or a device failure, thereby causing a rain or the like. When the reception power of the B station decreases, the transmission power of the A station is increased in accordance with the decrease of the reception power of the B station, thereby preventing signal quality deterioration due to the influence of thermal noise.
[0032]
Also, in the steady state where there is no rainfall or fading, when the reception power is reduced due to equipment failure, the A station and the B station forcibly fix the transmission power to a predetermined transmission power, for example, the minimum transmission power. Therefore, it is possible to prevent signal quality from being deteriorated due to interference with other adjacent transmission signals and nonlinear distortion of the transmission power amplifier.
[0033]
Next, transmission power control according to the present embodiment will be described using a time chart. FIG. 3 is a time chart showing transmission power control with respect to a decrease in received power due to rainfall. FIG. 4 is a time chart illustrating transmission power control with respect to a decrease in reception power due to selective fading. FIG. 5 is a time chart showing transmission power control with respect to a decrease in received power due to a failure in the receiving section of station A.
[0034]
3, 4, and 5, the propagation loss is the attenuation amount including the propagation loss of the transmission path, that is, the difference between the transmission power information and the reception power information. As a reference, the increasing direction of attenuation is shown in accordance with the decreasing direction of received power.
[0035]
First, control of the transmission power of the own station in response to a decrease in received power of the partner station due to rain will be described. FIG. 3A is a time chart showing the transmission power control of the A station with respect to the reception power of the B station due to propagation loss. FIG. 3B is a time chart showing the transmission power control of the B station with respect to the reception power of the A station accompanying the propagation loss. FIG. 3C is a time chart showing a COMP (comparison) output.
[0036]
In the case of rain, as shown in FIGS. 3 (a) and 3 (b), the received power decreases for both the A station and the B station as the bidirectional propagation loss increases. Then, in the A station, when the reception power of the B station becomes equal to or less than a predetermined threshold value, control is performed to increase the transmission power of the A station every 1 dB, for example, in accordance with a decrease in the reception power of the B station. Similarly, in the B station, when the received power of the A station becomes equal to or lower than a predetermined threshold, the transmission power of the B station is similarly increased by 1 dB in response to a decrease in the received power of the A station. I do.
[0037]
Here, the COMP & TIMER 54a transmits the propagation loss (| TPWR DATA-A |-| RPWR DATA-B |) in the transmission direction (A station → B station) and the propagation loss (| TPWR in the reception direction (A station ← B station)). DATA-B |-| RPWR DATA-A |) is calculated to obtain the difference between the two levels. Since the propagation loss due to rainfall has almost no level difference in both directions, the level difference (COMP output) is almost 0, that is, 0 dB, as shown in FIG. Thus, COMP & TIMER 54a outputs a control signal indicating normal operation (NORM). Based on this control signal, transmission power control is normally performed. That is, the A station and the B station perform control to increase the transmission power up to the maximum value according to the decrease in the reception power of each other. Further, when the propagation loss decreases and the reception power starts to increase, control is performed to decrease the transmission power according to the increase in the reception power of each other.
[0038]
Next, control of the transmission power of the local station with respect to a decrease in the reception power of the counterpart station due to selective fading will be described. FIG. 4A is a time chart showing the transmission power control of the A station with respect to the reception power of the B station accompanying the propagation loss. FIG. 4B is a time chart showing the transmission power control of the B station with respect to the reception power of the A station accompanying the propagation loss. FIG. 4C is a time chart showing a COMP (comparison) output.
[0039]
As shown in FIG. 4A, the received power of the station B is less than a predetermined threshold value although there is little influence of selective fading and there is some propagation loss. Therefore, the transmission power of station A remains controlled to a predetermined transmission power, for example, the minimum transmission power.
[0040]
On the other hand, as shown in FIG. 4 (b), the reception power of the station A is greatly affected by selective fading, and the reception power decreases to a threshold value or less, and the transmission power control of the station B is performed. .
[0041]
Here, the COMP & TIMER 54a transmits the propagation loss (| TPWR DATA-A |-| RPWR DATA-B |) in the transmission direction (A station → B station) and the propagation loss (| TPWR in the reception direction (A station ← B station)). DATA-B |-| RPWR DATA-A |) is calculated to obtain the difference between the two levels. Due to the influence of selective fading, the level difference (COMP output) becomes large as shown in FIG.
[0042]
However, since selective fading is generally temporary, if an ALM detection interval due to selective fading stops within the TIMER interval by setting an arbitrary duration (TIMER interval), COMP & TIMER 54a Thus, it is possible to output a control signal indicating normal operation (NORM) by classifying it as a device failure.
[0043]
Next, control of the transmission power of the own station in response to a decrease in the reception power of the partner station due to a failure of the receiving unit of the own station will be described. FIG. 5A is a time chart showing transmission power control of the A station with respect to reception power of the B station due to propagation loss. FIG. 5B is a time chart showing the transmission power control of the B station with respect to the reception power of the A station accompanying the propagation loss. FIG. 3C is a time chart showing a COMP (comparison) output.
[0044]
First, as shown in FIG. 5 (a), the reception power of station B is stable without attenuation due to rain or fading, does not fall below a predetermined threshold, and the transmission power of station A is controlled to the minimum transmission power. Has been.
[0045]
Next, as shown in FIG. 5B, the station A in which the receiving unit 30a has failed has a lower reception power and a lower value than the reception power of the station B. At this time, since the reception power of the A station is equal to or less than a predetermined threshold value, the B station performs control to increase the transmission power.
[0046]
Here, the COMP & TIMER 54a transmits the propagation loss (| TPWR DATA-A |-| RPWR DATA-B |) in the transmission direction (A station → B station) and the propagation loss (| TPWR in the reception direction (A station ← B station)). When DATA-B |-| RPWR DATA-A |) is calculated and the difference between the two levels is obtained, the level difference (COMP output) is clearly increased. In addition, unlike a fading, a device failure is rarely a temporary case and occurs beyond an arbitrary duration (TIMER section). Based on the determination result, the COMP & TIMER 54a outputs a forced control signal (CONT SIG-A) for controlling the transmission power to a predetermined transmission power, for example, the minimum transmission power, to the TPWR CONT 55a and transmits the transmission power of the B station to the minimum transmission power. In order to control to electric power, it outputs also to DATA CONV53a. Therefore, the A station and the B station can control the transmission power to a predetermined transmission power by the forced control signal (CONT SIG-A) that is output when a device failure is detected.
[0047]
In the above description, the transmission power control of the A station is performed based on the reception power of the B station, but the A station can also control the transmission power based on the reception power of the own station. FIG. 6 is a block diagram of a control unit when station A performs transmission power control based on the received power of the local station.
[0048]
According to FIG. 6, the COMP & TIMER 54a of the control unit 50a performs propagation loss (| TPWR DATA-A |-| RPWR DATA-B |) in the transmission direction (A station → B station) and the receiving direction (A station ← B station). The transmission loss information (TPWR DATA-A) is compared with the transmission power information (TPWR DATA-A) of the A station, but the propagation loss (| TPWR DATA-B |-| RPWR DATA-A |) is the same. DATA-A), and the transmission power is increased stepwise as the received power of the local station decreases.
[0049]
Usually, transmission / reception transmission between the A station and the B station uses a plurality of frequencies in the same frequency band and at regular intervals. Thereby, it is assumed that the propagation loss due to rainfall has a correlation regardless of the frequency, and a method of controlling the transmission power of the station A based on the reception power of the own station may be employed. The advantage is that the configuration is simplified and fast fading can be followed. However, if the transmission power of station A is only controlled based on the reception power of the own station, the transmission power of station B is not normally controlled, and the reception electric field of station A is lowered, resulting in signal quality degradation. is there.
[0050]
FIG. 7 is a time chart when station A performs transmission power control based on the received power of the local station. FIG. 7A is a time chart showing the transmission power control of the A station with respect to the reception power of the A station accompanying the propagation loss. FIG. 7B is a time chart showing the transmission power control of the B station with respect to the reception power of the B station accompanying the propagation loss.
[0051]
According to FIG. 7, the propagation loss increases due to rain or the like, and both the received electric fields at station A and station B decrease. Then, the station A increases the transmission power from the minimum transmission power in units of 1 dB when the reception power becomes equal to or less than the predetermined threshold value. Although the reception power of the station B decreases due to the rain, the station A increases the transmission power, and therefore does not fall below a predetermined threshold value, so that the transmission power remains controlled to the minimum power. Even if the propagation loss further increases, the same operation is repeated. Therefore, the transmission power of the B station remains controlled to the minimum power up to the maximum power that can control the transmission power of the A station. As a result, the reception electric field of station A is lowered, and signal quality is deteriorated due to the influence of thermal noise.
[0052]
Here, the COMP & TIMER 54a transmits the propagation loss (| TPWR DATA-A |-| RPWR DATA-B |) in the transmission direction (A station → B station) and the propagation loss (| TPWR in the reception direction (A station ← B station)). DATA-B |-| RPWR DATA-A |) is calculated to determine the difference between the two levels. When the station A detects a decrease in the received power of the own station, the level difference is small in the case of a propagation path failure. Is The transmission power of your station After fixing the default time Received Control that increases stepwise in response to a decrease in the received power is performed.
[0053]
In this control, when the station A increases the transmission power after a predetermined time is fixed, the increase amount is increased in stages, so that the station B performs the control to increase the increase amount of the transmission power in stages, and then the shortage amount is increased. Since the station A increases the transmission power, it is possible to prevent only one of the stations from increasing the transmission power. Further, when propagation loss increases, the same operation is performed, and only station A can perform balanced control without increasing transmission power. Accordingly, it is possible to prevent a decrease in received power of the A station due to rain while following changes in fading, and it is possible to prevent deterioration in signal quality in both the A station and the B station. On the other hand, in the case of a device failure with a large level difference, the station A and the station B perform control to forcibly fix the transmission power to a predetermined transmission power, as described above.
[0054]
Moreover, COMP & TIMER in a control part can be made into CPU. FIG. 8 is a block diagram showing a configuration in which a CPU is used in the control unit shown in FIG.
[0055]
According to FIG. 8, the CPU 57a can quickly determine whether a propagation path failure or an equipment failure is observed by monitoring a temporal change in bidirectional propagation loss. In particular, in the case of selective fading, there is a case where the reception power is reduced due to the state of the propagation path, that is, a frequency at which resonance occurs (hereinafter referred to as “notch”). At that time, if a notch is made for a long time in the frequency of communication between the opposite parties, the COMP & TIMER 54a determines that the device has failed if the alarm detection time (ALM detection section) is set long. However, the CPU 57a can quickly detect the selective fading that attenuates slowly and the detection of the equipment failure that suddenly decreases the received power at a certain time by monitoring the temporal change of the propagation loss. .
[0056]
【The invention's effect】
As described above, according to the transmission power control method and the transmission power control apparatus of the present invention, the transmission power and the reception power are monitored by the local station and the partner station, respectively, and it is determined whether a propagation path failure or a device failure. When the reception power is reduced, in the case of a device failure, the transmission power is forcibly controlled to a predetermined transmission power, so that it is possible to prevent interference with other lines due to the device failure.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a transmission power control apparatus of the present invention.
FIG. 2 is a block diagram showing a configuration of a control unit shown in FIG.
FIG. 3 is a time chart showing transmission power control with respect to a decrease in received power due to rainfall.
FIG. 4 is a time chart showing transmission power control with respect to a decrease in reception power due to selective fading.
FIG. 5 is a time chart showing transmission power control with respect to a decrease in received power due to a failure in a receiving section of station A.
FIG. 6 is a block diagram of a control unit when station A performs transmission power control based on the received power of the own station.
FIG. 7 is a time chart when station A performs transmission power control based on the received power of the own station.
8 is a block diagram showing a configuration in which a CPU is used in the control unit shown in FIG.
[Explanation of symbols]
10a, 10b Modulator (MOD-ENC)
20a, 20b Transmitter (TX)
30a, 30b receiver (RX)
40a, 40b Demodulator (DEC-DEC)
50a, 50b Control unit (ATPC CONT)
60a, 60b antenna
51a CONV
52a DATA CONV
53a DATA CONV
54a COMP & TIMER
55a TPWR CONT
56a CONV

Claims

A transmission power control method for controlling the transmission power of the local station based on the reception power of the counterpart station, monitoring the transmission power and the reception power of the local station and the counterpart station, and attenuation including bidirectional propagation loss based on the monitoring information Each level is calculated to obtain a level difference, and it is determined whether a propagation path failure or a device failure is based on the rate of change of each attenuation amount or the level difference. In the case of a propagation path failure with a small level difference, the local station increases the transmission power in response to a decrease in the reception power of the counterpart station. In the case of a device failure with a large level difference, the local station and the counterpart station transmit. A transmission power control method characterized by performing control for forcibly fixing power to a predetermined transmission power.

A transmission power control method for controlling the transmission power of the local station based on the reception power of the local station. The transmission power and the reception power of the local station and the other station are monitored, and attenuation including bidirectional propagation loss is detected by the monitoring information. Each level is calculated to obtain a level difference, and it is determined whether or not a propagation path failure or a device failure is based on the rate of change of each attenuation amount or the level difference. In the case of a propagation path failure where the level difference is small, the own station increases its transmission power step by step in accordance with a decrease in its own received power after fixing its own transmission power for a predetermined time. A transmission power control method characterized in that in the case of a large equipment failure, the local station and the partner station perform control to forcibly fix the transmission power to a predetermined transmission power.

A transmission power control device that controls transmission power based on the reception power of the local station or the partner station, and receives an ATPC control signal including transmission power information and reception power information of the partner station, and receives a reception power monitor signal of the local station A receiving unit for outputting, a demodulating unit for demodulating the output of the receiving unit, received power information of the own station converted from the received power monitor signal of the own station, or received power information of the counterpart station extracted from the demodulated unit output A control unit that outputs a transmission power control signal that increases transmission power when the reception power of the local station or the partner station decreases based on the transmission power information of the local station generated by the control unit and the reception power of the local station A modulation unit that takes in information and outputs an ATPC control signal; and a transmission unit that converts the modulation unit output into a transmission signal and then amplifies and outputs the transmission signal based on the transmission power control signal. The controller determines whether there is a propagation path failure or a device failure based on the transmission power information and reception power information of the counterpart station and the transmission power information of the local station and the reception power information of the local station. When a decrease in received power occurs, in the case of a propagation path failure, the transmission power control signal that increases the transmission power in response to a decrease in the received power of the own station or the partner station is output. Outputs a transmission power control signal fixed to a predetermined transmission power to the transmission unit and outputs a forcible control signal to notify a partner station.

The control unit calculates a level of attenuation including bidirectional propagation loss based on the transmission power information and reception power information of the counterpart station and the transmission power information of the local station and the reception power information of the local station. 5. The transmission according to claim 4, wherein a difference is obtained and a propagation path failure is determined when the level difference is within a predetermined value range, and an equipment failure is determined when the level difference exceeds a predetermined value range. Power control device.

The control unit calculates an attenuation amount including a bidirectional propagation loss based on the transmission power information and reception power information of the counterpart station, the transmission power information of the local station, and the reception power information of the local station, and 5. The transmission power control apparatus according to claim 4, wherein a temporal change is monitored, a propagation path failure is determined when the temporal change is slow, and an equipment failure is determined when the temporal change is early.

The control unit outputs the transmission power control signal for increasing the transmission power to the transmission unit in the case of a propagation path failure when a decrease in the reception power of the counterpart station occurs. 5. The transmission power control signal fixed to a predetermined transmission power for the transmission unit is output, and a compulsory control signal for notifying a counterpart station is simultaneously output to the modulation unit. 5. The transmission power control device according to 5 or 6.

In the case of a propagation path failure when the reception power of the local station is reduced, the control unit fixes the transmission power of the local station after fixing the transmission power of the local station for a preset time. The transmission power control signal that increases stepwise according to the decrease is output, and in the case of a device failure, the transmission power control signal that is fixed to a predetermined transmission power is output to the transmission unit, and the 7. The transmission power control apparatus according to claim 4, wherein a compulsory control signal to be notified to the counterpart station is simultaneously output to the modulation unit.