Estimation of Coded Antijam Performance with Nonlinear Processing

The utility of the Chernoff bound developed by Omura and Levitt for evaluating antijam performance of coded spread-spectrum systems is enhanced by a Monte Carlo estimation procedure which has some similarity to an adaptive algorithm. The applicability of this new procedure to obtaining numerical results is illustrated for frequency-hopping spread-spectrum systems with nonlinear processing to protect against partial band jamming strategies. In particular, power normalization and clipping algorithms which do not depend on AGC averaging in the receiver can be defined and evaluated without necessity for actual decoder simulations and despite difficulty of analytical approaches when such nonlinear processing schemes are employed. Representative results indicate that satisfactory protection can be achieved against partial-band jamming, in the sense that the worst case is not significantly degraded from that of white Gaussian noise.