Spread Spectrum Communications In Non Gaussian Channels

Spread-Spectrum Communications in Non-Gaussian Channels

The overall purpose of this research project was to seek new methods for improving the robustness and efficiency of spread-spectrum communications systems operating over non-Gaussian channels. The study was motivated in large part by the fact that modern military radio networks must operate in complex and variable noise environments that are often dominated by impulsive, non-Gaussian man-made noise sources. The research under this contract progressed in three basic areas: (1) optimum multiuser demodulation techniques; (2) direct-sequence spread-spectrum multiple-access (DS/SSMA) signaling through impulsive channels; and (3) improved suppression of narrowband interferers from spread-spectrum signals. The common thread binding these three disparate multiuser-communications research topics is the fact that each involves the processing of signals in non-Gaussian interference. In the first case, the non-Gaussian interference is the multiuser noise interfering with the demodulation of a given user; in the second case, the non-Gaussian interference is the impulsive noise dominating the channel; and in the third case, the non-Gaussian interference is the spread-spectrum signal itself as it interferes with the prediction and consequent excision of the narrowband interferer. (rh).

Research in Progress

Vols. for 1977- consist of two parts: Chemistry, biological sciences, engineering sciences, metallurgy and materials science (issued in the spring); and Physics, electronics, mathematics, geosciences (issued in the fall).

Research in Progress