We consider the detection of direct-sequence spread spectrum signal received in pulsed noise jamming enviromment. The Expectation- Maximization Algorithm is used to estimate the unknown jammer parameters and hence obtain a decision on the binary signal based on the estimated IikeIihood functions. The probability of eerror performance of the algorithm is simulated for a repeat code and a (7,4) block code. Simulation results show that at low signal to thermal noise ratio and high jammer power, the EM detector performs significantly better than the hard limiter and somewhat better than the soft limiter. Also, at low SNR, there is little degradauon as compared to the maximum-likelihood detector with true jammer parameters. At high SNR, the soft limiter outperforms the EM detector.