at will allow it to achieve the desired performance under the Table 2.11 Parameters associated with performance of FH/MFSK signals with optimum diversity in worst case independent multitone jamming, as defined in (2.115) and (2.127). .37 or .74 3.4 or .69 Non-Coherent Frequency-Hopped Systems WC INDEPENDENT MULTITONE JAMMING WC n=1 BAND MULTITONE JAMMING WC n=2 BAND MULTITONE JAMMING BROADBAND NOISE WC PARTIAL- BAND NOISE (EXACT Pp ) WC n s M = 4 BAND MULTITONE JAMMING Eb/Nj, dB Figure 2.62. Relative performance of FH/4-ary FSK signalling with optimum diver- sity in different worst case jamming environments. Note that the optimum diversity varies with the type of jammer for a given E/N. WC n= I BAND MULTITONE JAMMING WC INDEPENDENT MULTITONE JAMMING WC n=2 BAND MULTITONE JAMMING WC PARTIAL- BROADBAND BAND NOISE NOISE (EXACT P. ) WC n=M = 8 BAND MULTITONE JAMMING Eb/Nj,dB Figure 2.63. Same as Figure 2.62, but for 8-ary FSK. Coding Countermeasures WC n=1 BAND JAMMING MULTITONE MOPT=4 MOPT = 6 WC INDEPENDENT MULTITONE WC n= 2 JAMMING WC PARTIAL MULTITONE (NOISE JAMMING WCn=M=16 MULTITONE "OPT = 10 JAMMING BROADBAND NOISE MOPT=13 (EXACT Ph ) Eb/Nj,dB Figure 2.64. Same as Figures 2.62 and 2.63, but for 16-ary FSK. To emphasize the variation in optimum diversity Mopt with jammer type, values of Mopt are indicated for EIN, = 10 dB. worst conceivable jamming conditions. With the possible exception of K = 1 as discussed above, this implies the assumption of n = 1 band multitone jamming. However, since this class of jammer has the lowest 8 for a given K, it calls for less diversity than is optimum for the other kinds of jamming. So we must verify that the suboptimum, degraded performance for these other jammers does not exceed the optimized P for n = 1 band multitone jamming. This kind of information is not available from curves of the form of Figures 2.62-2.64. As an example, using Table 2.10, we see that .4493; n = 1 band multitone jamming, K = K type of jammer (2.129) On this basis, it is reasonable to use K = 3, and if