LPI detection of frequency-hopping signals using autocorrelation techniques
Abstract
Interception of frequency-hopping (FH) waveforms is commonly achieved by using a set of radiometers (energy detectors) that individually energy-detect 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 wide-band additive Gaussian noise (AWGN) using samples from the autocorrelation domain. It is shown that, under fairly general operational assumptions, an appreciable gain in decision signal-to-noise 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 likelihood-ratio test, has the advantage of reduced complexity. The overall approach has been motivated by the recent implementational feasibility of large-time-bandwidth-product real time correlators such as surface-acoustic 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