アナログ通話路におけるスペクトラムスクランブル秘話への送受同形エンファシスの適用

Abstract

The mobile communication has the danger that the content of communication is intercepted, therefore, the encryption which protects confidentiality has been studied from various approaches. The existing method which was merely adding an encryption function, increases effective modulation index above the level of without encryption, and brings on a spread of radio frequency bandwidth. It is already reported that effective modulation index is maintained, when isomorphic emphasis applies to spectrum inversion encryption. This paper establishes that isomorphic emphasis maintains aforementioned feature, even if it applies to arbitrary spectrum scramble pattern, and it can be realized simple circuit. And this circuitry configuration is the most economical when it introduced into PM transmission.