TRANSMISSION TECHNIQUE PERFORMANCE AND CHANNEL RELATIONSHIPS IN DATA COMMUNICATION.
Abstract
Selected data modem techniques and recently envolved channel characterizations are surveyed and annotations are made for comparative evaluations of data transmission techniques. First, fundamental relations are reviewed and unified with emphasis on their physical interpretations as they apply to technique performances and channel parameters. This is done by describing phenomenologically low-frequency, high-frequency, microwave, and troposcatter radio channels and ascribing, where possible, deterministic and nondeterministic characterizations to them. Parameters giving measures of various important phenomena are inferred from the characterizations and are interpeted physically. Particular attention is given to time- and frequency-selective fading normally observed in high-frequency and troposcatter channels and also observed in microwave or other line-of-sight channels in the presence of objects such as planes moving through the path of transmission. Next, representative data modem techniques are presented and compared for various combinations of channel parameters and levels of implementation complexity. Finally, based on the foregoing review, consideration is given to selected modems both in existence and in development. This is done by describing the distinguishing features of the modems and then, when possible, presenting both predictions and experimental validations. Specific tests that graphically illustrate the importance of time- and frequency-selective fading in modem technique performance are stressed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1969
- Accession Number
- AD0690607
Entities
People
- Robert C. Waag
Organizations
- Rome Laboratory