Security considerations in frequency hopping radio systems

As far as jamming and security are concerned, the following types of jamming have been considered: (a) repeater jamming, (b) single tone jamming, (c) multitone jamming, and (d) wideband and partial-band noise jamming. For the purpose of performance evaluation, two channel models are required: a wideband UHF propagation model and a narrowband HF channel model. There is no single jamming waveform that has the same effect on all spread-spectrum systems and there is no single spread-spectrum system that has the same performance for all types of jamming. It is also assumed that the jammer has a priori knowledge of all relevant signalling parameters, with the exception of the hop set sequences