Non-linear distortion in transmission systems

Le résumé fourni par la source

The problem of the distortion noise generated by a signal in its transmission through one or more non-linear devices is analysed. This subject has become of increasing importance in connection with the development of the transmission of different types of signals on a multi-channel basis through a common network, e.g. modulator, amplifier or transmitter. The provision of such networks is now of frequent occurrence, and in order that economic and satisfactory designs may be obtained it is essential to be able to determine precisely the effect of non-linearity and also the limiting linearity requirements, preferably in a form which can be readily comprehended and applied by designers. The problem has been considered to be very complex, and existing literature is both scanty and involved. This paper presents a simple solution, which is capable, in general, of immediate application to any type of complex signal (e.g. speech, music, television, voice-frequency telegraphy or thermal noise) covering any frequency band or frequency allocation. The results are presented to the designer in the form of the limiting levels of the various harmonics of a single tone, which levels must not be exceeded if the noise power from the non-linear device in any specified frequency band is not to exceed a predetermined value. The differences in the linearity requirements of a single amplifier and of a repeatered system are demonstrated. Provided the input/output characteristic of the network can be expressed as a single-valued power series independent of the frequency in the working band, the results obtained should cover with adequate accuracy the design of all types of transmission systems.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.