An information-theoretic study of ratio-threshold antijam techniques

The performances of ratio/threshold (R/T) antijam communication systems in the presence of different jamming strategies are studied. Frequency hopping spread spectrum (FH/SS) binary frequency shift keying (FSK) modulation is used for the transmitted signal. Comparisons with a hard decision receiver are made. Channel capacity, cutoff rate and coded bit error probability are used as measures of the performance. A game theoretic problem with two players, transmitter and jammer is formed. The transmitter can choose either fixed threshold or random threshold as its strategy. The jammer with fixed finite power has either one dimensional jamming or partial band jamming as its strategy. The payoff function of the game is channel capacity or cutoff rate. Using R/T technique, performance considerably superior to that possible with a hard decision receiver vs one dimensional jamming channel or partial band jamming channel can be obtained.