アナログ通信路を対象としたスペクトラム反転への送受同系エンファシスの提案と雑音抑圧効果

Abstract

In order to guard against infringement of confidentiality in mobile communication, the idea of adding an encryption function to radio communications had been studied from various approaches. Unfortunately, however, the existing methods have defect which the frequency occupancy bandwidth is enlarged by the increase of effective modulation index, or which complicated circuits is implemented in huge economical cost. With such a background in mind, this investigation establishes an appropriate circuitry realization method and economical optimum configuration for the new isomorphic emphasis. It has been given that isomorphic emphasis suppress the noise power well, even if a spectrum inversion encryption is introduced into PM transmission.