Accession Number : ADA300627
Title : Spread Spectrum Modulation by Means of Time-Varying Linear Filtering.
Descriptive Note : Final rept.,
Corporate Author : NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA
Personal Author(s) : Dyckman, Howard L.
PDF Url : ADA300627
Report Date : MAR 1995
Pagination or Media Count : 24
Abstract : Time-varying linear filtering can be used to generate a broad class of spread spectrum signals which includes Direct Sequence spread spectrum as a special case. The technique is based on a fflter of arbitrary length whose impulse response changes rapidly It can spread the data signal in time as well as in frequency, thereby introducing a form of protection from errors similar to error-correcting coding and interleaving. Time-varying filter (TVF) systems can produce a broad range of noise-like waveforms and can be designed to minimize spillover into adjacent frequency regions. These properties should provide benefits in defense as well as in civilian radio communication systems.
Descriptors : *SIGNAL PROCESSING, *FREQUENCY MODULATION, *LINEAR FILTERING, *SPREAD SPECTRUM, MATHEMATICAL MODELS, OPTIMIZATION, DATA TRANSMISSION SYSTEMS, TIME DEPENDENCE, SIGNAL TO NOISE RATIO, WAVEFORMS, WHITE NOISE, GAUSSIAN NOISE, INPUT OUTPUT PROCESSING, TRANSFORMATIONS(MATHEMATICS), FREQUENCY BANDS, ELECTROMAGNETIC WAVE FILTERS, TRANSVERSE WAVES, GREENS FUNCTIONS, MATCHED FILTERS, DEMODULATION, TIME DOMAIN, ERROR CORRECTION CODES, RADIOFREQUENCY FILTERS, FREQUENCY SHIFT.
Subject Categories : Radiofrequency Wave Propagation
Distribution Statement : APPROVED FOR PUBLIC RELEASE