報告書番号

R01

タイトル（和文）

ディジタルマイクロ波回線における伝搬路障害，歪みならびに不稼働率に関する研究

タイトル（英文）

PROPAGATION IMPAIRMENT DISTORTION AND UNAVAILABILITY ON DIGITAL MICROWAVE LINKS

概要 （図表や脚注は「報告書全文」に掲載しております）

ディジタルマイクロ波回線の設計やルート選定，運用などに資するため，伝搬路で生ずる障害（劣化）や歪みに関する影響予測手法，ならびに電力用ディジタルマイクロ波回線におけるフェージング時の所要伝送品質やシステム信頼度の解析手法を開発し，それらの有用性を示した。（１）多重波干渉フェージングによる影響の解析と予測伝搬歪みを発生させる多重波干渉フェージングについて，伝送帯域内の振幅偏差から回線瞬断率を推定する手法を開発した。また，反射板中継方式を用いた回線について，多重波干渉フェージング時の伝搬特性を理論的に解明した。さらに，気象データを用いた統計的なフェージング発生予測手法を開発した。（２）人工建造物による影響の解析と予測人工建造物によりシステムゲインとなる場合として，反射板中継方式において反射板がフレネル領域に設置されている回線の反射板利得の精密な計算法を開発した。建造物が伝搬路を

概要 （英文）

WE DEVELOPED,METHODS FOR EVALUATING THE EFFECTS OF PROPAGATION IMPAIRMENT AND DISTORTION ON DIGITAL MICROWAVE LINKS. WE ALSO EVALUATED THE BIT ERROR RATIO REQUIREMENT OF DIGITAL MICROWAVE LINKS FOR ELECTRIC UTILITIES AND ANALYZED THE SYSTEM RELIABILITY,AND VALIDITY. (1)ANALYSIS AND PREDICTION OF INFLUENCE OF MULTIPATH FADING AMETHOD WAS DEVELOPED FOR PREDICTING OUTAGE PROBABILITY DUE TO MULTIPATH FADING USING THE DISTRIBUTION OF IN-BAND LINEAR AMPLITUDE DISPERSION.MULTIPATH PROPAGATION CHARACTERISTICS OF MICROWAVE LINKS WITH A REFLECTOR AS A PASSIVE REPEATER WERE CLARIFIED. A STATISTICAL METHOD WAS DEVELOPED FOR FORECASTING MICROWAVE FADING BASED ON METEOROLOGICAL DATA. (2)ANALYSIS AND PREDICTION OF INFLUENCE OF MAN-MADE STRUCTURES A PRECISE METHOD WAS DOVELOPED FOR CALCULATING REFLECTOR GAIN ON REFLECTOR-EQUIPPED CIRCUITS OPERATING IN THE FRESNEL REGION,WHERE AN ANTENNA-REFLECTOR COMBINATION INCREASES THE SYSTEM GAIN. PROPAGATION IMPAIRMENTS DUE TO MAN-MADE STRUCTURES WERE ANALYZED WHERE SUCH STRUCTURES SCREEN,REFLECT OR SCATTER MICROWAVES AND INTERFERE WITH COMMUNICATIONS DECREASING SYSTEM GAIN. EVALUATION METHODS WERE DEVELOPED IN TERMS OF EQUIVALENT C/N DEGRADATION. DEGRADATION OF CROSS-POLARIZATION DISCRIMINATION DUE TO SCATTERING BY CONDUCTORS WAS CLARIFIED. (3)ERROR RATIO REQUIREMENT OF DIGITAL MICROWAVE LINKS FOR ELECTRIC UTILITIES AND SYSTEM RELIABILITY ANALYSIS DIGITAL MICROWAVE LINKS USED FOR PCM CURRENT DIFFERENTIAL TELEPROTECTION SYSTEMS WERE ANALYZED. THE BIT ERROR RATIO REQUIREMENT WAS 10**-6 10**-7. A MEASURE IS PROPOSED FOR EVALUATING SYSTEM RELIABILITY OR FUNCTIONAL AVAILABILITY OF WIDE-AREA DISTRIBUTED CONTROL DATA NETWORKS EMPLOYING DIGITAL MICROWAVE LINKS TAKING PROPAGATION AVAILABILITY INTO ACCOUNT. VARIOUS CONTROL DATA NETWORKS WERE ANALYZED.

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