EVALUATION OF SPECIAL MODULATION TECHNIQUES. VOLUME I.
Abstract
This report provides a theoretical basis for the selection of optimum modulation techniques for digital data transmission over HF and troposcatter point-to-point communication links, and evaluates modulation techniques suitable for medium altitude and synchronous satellites serving a multiplicity of users. For HF transmissions, signal selection techniques are considered which are completely compatible with present independent sideband transmissions of four 3-kc nominal bandwidth channels. A channel multipath structure is assumed which consists of two equal strength independent Rayleigh fading paths, providing different delays and doppler shifts. Multichannel transmissions are considered and the resultant interchannel and intersymbol interference for several embodiments of PSK and FSK modulation are calculated. In the analysis of data transmissions over troposcatter, the existing FDM multiplex configurations are discarded in favor of a high speed TDM approach. A gaussian channel multipath distribution and receiver generated additve noise disturbances are assumed, and binary and M-ary PSK and FSK modulations are considered. For both media, the results of the modulation technique evaluation are presented in both graphical and tabular form.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1964
- Accession Number
- AD0486865