LPI detection of frequencyhopping signals using autocorrelation techniques
Abstract
Interception of frequencyhopping (FH) waveforms is commonly achieved by using a set of radiometers (energy detectors) that individually energydetect subbands of the total spread bandwidth of the suspected transmission. In this paper, a scheme is analyzed which can improve the detection performance of FH waveforms in wideband additive Gaussian noise (AWGN) using samples from the autocorrelation domain. It is shown that, under fairly general operational assumptions, an appreciable gain in decision signaltonoise ratio (SNR) can be achieved over that of the radiometer. This gain is proportional to gamma(H) squared, where gamma(H) is the hop SNR. The proposed algorithm, albeit inferior to the optimal likelihoodratio test, has the advantage of reduced complexity. The overall approach has been motivated by the recent implementational feasibility of largetimebandwidthproduct real time correlators such as surfaceacoustic wave devices (SAWDs).
 Publication:

IEEE Journal on Selected Areas in Communications
 Pub Date:
 September 1985
 Bibcode:
 1985IJSAC...3..714P
 Keywords:

 Autocorrelation;
 Frequency Hopping;
 Interception;
 Signal Detection;
 Correlators;
 Digital Simulation;
 Probability Distribution Functions;
 Random Noise;
 Signal To Noise Ratios;
 White Noise;
 Communications and Radar