Interference Performance Degradation to Digital Systems

The performance degradation of noncoherent, nonerror correcting digital communication systems from simulated AM, FM, SSB and pulsed interference is examined. The on-off keyed (Al), frequency shift keyed (F1), frequency shift keyed amplitude modulated (A2) and pulse code modulated FM (F9) digital communication systems are examined for errors of commission (false alarm) and omission (false dismissal). The most susceptible digital modulation system that was examined was Al. The simulated SSB interference caused the worst degradation to all the communication systems. The results of the SSB interference measurements closely agree with the theoretical results for narrowband noise. The results of this analysis show that the digital communication systems examined have error probabilities less than one part in 10⁴ for on-tune signal-to-interference power ratios of 11 dB or greater.