Criteria for an Optimum Receiver for Use with a Temporally Unstable Medium.
Abstract
The problem of receiving intelligence through a medium whose properties are time varying has become an important one recently as communication techniques are extended to the upper atmosphere, or troposphere, and to the underwater domain of submarines. Both the tropospehre and sea water are time varying in a number of ways, and the time variations have a wide range of characteristic periods. Some of these are long, such as the diurnal and seasonal variations of underwater sound velocity profiles. Others are quite short and may result from magnetic storms and solar flares, which affect the ion density of the troposphere, or the wave motion of the seawater surface and the relative motion of different underlying layers of water. This paper is concerned with such short-time temporal instabilities, namely, those that have an opportunity to distort the time base of a transmitted or received signal (waveform) during the time duration of the coded signal. Such distortions, even though slight, can be expected to play havoc with the usual type of matched filter or correlator receiver, which is actually an optimum receiver when temporal distortions are not present.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 14, 1963
- Accession Number
- ADA068794
Entities
People
- Ross E. Williams
Organizations
- Columbia University