Anti-jam performance of coded spread spectrum systems

Modern military communications systems are extensively using spread spectrum technique to offset the effect of jammers. However, for each type of spread spectrum signaling waveform, there is an optimum jamming strategy which will seriously degrade the channel performance. Coding offers a good solution to the jamming sensitivity by making the waveform unstructured. The anti-jam (AJ) performance of two coded spread spectrum systems is evaluated. The performance of spread spectrum systems using convolutional codes with Viterbi decoding have long been studied and recognized. However, long block codes can give competitive results. The simulation results for a class of rate 1/3, rate 1/2 and rate 2/3 quasi-cyclic codes with pseudo-noise and frequency hop spread spectrum systems will be presented.