THE TWO-FREQUENCY MEASUREMENT OF LINEOF-SIGHT SPREAD CHANNELS
Abstract
An analysis is carried out of the effects of various non-ideal circumstances on the two-tone method of measuring the two-frequency correlation function for microwave line-of-sight communication channels. These circumstances are the presence of both shortterm and long-term instabilities of the signal sources, the presence of additive noise, and the use of discontinuous tones such as those available from a spinning satellite. It is shown that oscillator instability effects are removable by assigning the short-term carrier oscillator instabilities to the channel, using high quality modulating oscillators and including phase-lock tracking loops, that the effect of additive noise can be made negligible provided the signal-to-noise power ratio of the received tones is greater than about 6 db, and that the use of discontinuous slowly-switched tones is distinctly disadvantageous. A method of processing the received tones is suggested which automatically removes the large constant delay due to range, leaving only the frequency dependent part of the delay.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 17, 1965
- Accession Number
- AD0616528
Entities
People
- M. L. Burrows
Organizations
- Massachusetts Institute of Technology