Secur, Classification of This Page Report Documentation Page

19. ABSTRACT (Continue on reverse if necessary and identify by block number) Several block and convolutional coding options are considered which are applicable to the noncoherent detection of FH/MFSK signals in the presence of tone jamming. The tone jamming model used in this report is the worst-cast tone jamming for an uncoded system. Using decoded probability of bit error as a performance criterion, we show that large signaling alphabets yield poor performance in a tone jamming environment. Furthermore, when hard-decision quantization is used, the degradation of a coded system in tone jamming over worst-case partial band noise jamming is the same as the corresponding degradation for the uncoded system: 4.3 dB for M=2, 6.3 dB for M=4, 8.3 dB for M=8, and increasing thereafter without bound as M-> = . The poor performance of coded systems with hard-decisions in tone jamming can be improved by about 10 dB by using soft-decision quantization assisted by perfect jammer state side-information. For the binary case the results obtained by using soft-decision quantization are about 1 dB better than those obtained for the partial band noise channel, showing that the worst-case channel for the uncoded system is not necessarily the worst-case channel for a coded system when side-information is available. (Continues) 20 DISTRIBUTION/AVAILABILITY OF ABSTRACT IS UNCLASSIFIED/UNLIMITED D SAME AS RPT n DTIC USERS 22a NAME OF RESPONSIBLE INDIVIDUAL P. J. Crepeau 21. ABSTRACT SECURITY CLASSIFICATION UNCLASSIFIED 22b. TELEPHONE (Include Area Code) (202) 767-3397 22c. OFFICE SYMBOL Code 7523 DDFORM 1473,84 MAR 83 APR edition may be used until exhausted All other editions are obsolete.