Accession Number : ADA116797

Title :   Measured Performance of a Delay Lock Tracking Loop when Noise Power Exceeds Signal Power.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Hanratty,Joseph Michael

PDF Url : ADA116797

Report Date : Mar 1982

Pagination or Media Count : 83

Abstract : In the communications area there is a general interest in recovering signals below the noise level. In the military this interest translates to low-probability-intercept (LPI) and anti-jam (AJ) communications systems. The receiver improves the signal-to-noise ratio so data can be reliably recovered. This improvement is usually accomplished by matched filtering or by correlation. In this report correlation is used as a post-detection processing technique to derive a synchronous reference. The system considered in this experiment can operate noncoherently by means of a delay lock tracking loop at signal-to-noise ratios as small as -5.0 to -7.1 dB. Furthermore, synchronization is achieved while the received signal is being modulated by data. No preamble or other type of synchronization is required.

Descriptors :   *Digital communications, *Signal to noise ratio, *Secure communications, Antijamming, Interception, Synchronization(Electronics), Correlation techniques, Delay lines, Signal processing, Theses

Subject Categories : Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE