Note on FM transmission of video between moving vehicles over a flat earth

A signal-to-interference ratio for the transmission of scanned images and digital data in the dynamic multipath environment was derived in an earlier paper. The dynamic case depends upon a Doppler environment-signal parameter ratio, while the static result is independent of the signal structure. The dynamic case is asymptotic to, but always worse than, the static one. For a Doppler-signal ratio of less than 10 percent the dynamic signal-to-noise ratio is essentially equal to the static one. Most real systems today fall in this region. This indicates why certain simple multipath analyses in use today have been successful. The method of designing a signal to fall below the 10-percent value is indicated. Signal-to-noise ratio curves are provided for system design purposes. These results permit system analysis and tradeoff studies to be based on earth reflection coefficient distributions and aircraft or satellite operation envelopes.