ry MFSK Error Correction Coding Technique NT = = 8 NT = 106; RRR = 80 NT = 107; Rh = 80 NT = 106; Rh2R = 80 No Coding (R=1) = 59.3 dB 59.1 dB 62.9 dB 59.1 dB p = .085 PB-MTJ FB-NJ p = .59 PB-NJ FB-NJ R = 1/2 Convolutional Coding 63.0 dB 59.1 dB 63.0 dB 59.1 dB p = .60 PB-NJ FB-NJ p = .60 PB-NJ FB-NJ Dual-3 Convolutional Coding 65.3 dB 59.7 dB 65.3 dB 61.8 dB FB-NJ p = .93 PB-MTF FB-NJ FB-NJ p = Fraction of Total Band Jammed PB-MTF = Partial-Band Multitone Jamming PB-NJ = Partial-Band Noise Jamming FB-NJ = Full-Band Noise Jamming R = Data Bit Rate Eb = ST = Energy Per Information Bit R = Rb/3 = Data Symbol Rate RHIR = Number of Hops Per Symbol Further Discussion 1.3.3 Optimum LPI Modulation/Coding Conditions Having now reviewed the intercept detectability and AJ performance of the various modulation and coding methods, a final conclusion may be drawn. The use of FH/PN versus pure FH has been shown to be of no advantage and, since it represents additional communication system complexity, espe- cially in terms of receiver acquisition and tracking functions, FH becomes the recommended SS approach. The remaining issue is the choice of hop rate. three criteria may be applied. The first involves a restatement of the conditions which preclude the interceptor's use of a channelized detector; namely, for finite duration messages, it is essential to minimize the number of hop slots per message relative to the total number of possible hop slots NT = WSSIR To satisfy the first criterion: Hop Rate < (Total Slots) (100 X Message Time). A second hop rate criterion is dictated by the number of hops per coded sym- bol that must be employed to obtain good AJ protection, namely: Hop Rate 4 X (Symbol Rate). Thus, the first two criteria, respectively, bound the hop rate to upper and lower values. The third criterion involves minimization of the message receiver non-coherent combining loss. Clearly, the fewer the number of hops per symbol, the lower the non-coherent combining loss and, there- fore, the lower the communicator's EIRP. Th