Interception of FH spread-spectrum signals: performance advantages of cycle detectors

The interception of weak frequency-hopped (FH) spread spectrum signals corrupted by broadband noise with unknown and changing power spectral density level is discussed. The doubly stochastic processes are considered to model the noise level as a random variable. The deflection is utilized to compare the performances of the conventional radiometer and the recently proposed single-cycle detector. The results confirm that, for long collect times, the single-cycle detector can outperform the radiometer for relatively small uncertainty in the noise level. Moreover, the conditions are thus established for the bit rate and the carrier frequency separation to assure a significant superiority of the single-cycle detector