Accession Number:

ADA222231

Title:

Measured Effects of Repeater Jamming on Direct-Sequence Spread Spectrum Receivers That Use Envelope Detectors

Descriptive Note:

Master's thesis,

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1989-09-01

Pagination or Media Count:

68.0

Abstract:

The effects of repeater jamming on a direct sequence spread spectrum communications system that uses an envelope detector were experimentally determined. A friendly signal transmitter, jamming signal transmitter, noiseless channel, and receiver were designed, built and tested. The spreading sequences of the friendly and jamming transmitters modulated a carrier to create an on-off keyed OOK signal. The OOK signal from the jammers was delayed and added to the friendly signal. The delays ranged from zero to 4 chips, and the JS ratios ranged from -20 to 20 dB. This signal was then envelope detected and correlated with a replica of the spreading sequence of the transmitters. The results of the correlation show that in instances of high jamming and low jamming, reliable communication should occur. In cases where the jammer power and friendly signal power are nearly equal, the output of the correlator will not produce a signal that allows for correct tracking and therefore will not provide reliable communications. rh

Subject Categories:

  • Countermeasures

Distribution Statement:

APPROVED FOR PUBLIC RELEASE