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):
Report Date:
1995-03-01
Pagination or Media Count:
24.0
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
- Operations Research