Microwave radio links

The paper deals with the general theory and design of microwave radio links as transmission systems. After a brief introduction, the questions of propagation and atmospheric phenomena are outlined in so far as they affect the design of a link. There is then given a treatment of a frequency-modulated multichannel radio link in which thermal and intermodulation noise are calculated in terms of the system parameters. This work makes possible the determination of the deviation for minimum total noise. In a particular case of practical importance a merit factor of a link is defined. The problem of pre-emphasis is outlined, and finally the required bandwidth is determined. The problems of a television link are discussed. In order to present a clear picture of the overall action, problems of a statistical character have been omitted. In particular, all occupied channels are assumed to have signals of equal amplitude. It follows that more work needs to be done to obtain design data for systems in which the statistical effects are important.