Accession Number : ADA292231

Title :   Improved Interception Capability Through the use of Transform Domain Processing.

Descriptive Note : Final rept. 22 Mar 91-21 Sep 94,

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA

Personal Author(s) : Milstein, L. B.

PDF Url : ADA292231

Report Date : MAR 1995

Pagination or Media Count : 183

Abstract : The research conducted during the course of this grant was devoted to two basic problems. The first was that of designing and analyzing an enhanced radiometer possessing the capability of intercepting a signal which is embedded in narrowband interference. The essence of the design was to precede the radiometer with a narrowband interference suppression filter; this allowed the receiver to null out most of the energy of the interference before it entered the radiometer, with the net result being an intercept receiver with much lower false alarm probability. The second major topic that was studied dealt with the design and performance analysis of code division multiple access (CDMA) systems for military communications. This topic was chosen because it complemented the former research area of interception, in the sense that the two together provided coverage of the essence of military communication needs (i.e., knowledge of the enemy's signaling, and security of one's own signaling). The research on CDMA included optimizing the chip rate of a direct sequence system when used over a frequency selective fading channel, and designing an enhanced coarse acquisition system to allow synchronization in the presence of narrowband interference.

Descriptors :   *RADIOMETERS, *RADIO COUNTERMEASURES, *RADIO INTERCEPTION, REQUIREMENTS, MILITARY REQUIREMENTS, OPTIMIZATION, DETECTORS, PROBABILITY, INTERCEPTION, ENERGY, PERFORMANCE TESTS, RATES, CHIPS(ELECTRONICS), FALSE ALARMS, SEQUENCES, MOBILE, RECEIVERS, INTERFERENCE, EMBEDDING, COMMUNICATION AND RADIO SYSTEMS, FAST FOURIER TRANSFORMS, MILITARY APPLICATIONS, FILTERS, CHANNELS, TRANSMITTER RECEIVERS, FREQUENCY RESPONSE, SUPPRESSION, NARROWBAND, SURFACE ACOUSTIC WAVES, FADING(ELECTROMAGNETIC WAVES).

Subject Categories : Radiofrequency Wave Propagation
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE