2 CONVOLUTIONAL CODE DUAL-2, RATE 1/3 CONVOLUTIONAL CODE 4-ARY CONVOLUTIONAL CODE UNCODED (7, I/2) 4-ARY CONVOLUTIONAL Eb/Nu,dB Figure 2.88. Same as Figure 2.87, but for K = 2. Again, with optimum diversity, we see that the dual-K system performance is negligibly affected by the code rate; in fact, we show in the text that this statement is asymptotically true for small Pb's for any K and all code rates 1/v. WC PARTIAL-BAND NOISE OPTIMUM DIVERSITY DUAL- 3, RATE 1/2 CONVOLUTIONAL CODE DUAL -3, RATE 1/3 CONVOLUTIONAL CODE 8-ARY ORTHOGONAL CONVOLUTIONAL CODE UNCODED (7, I/2) 8-ARY CONVOLUTIONAL Eb/N, Figure 2.89. Same as Figure 2.87, but for K = 3. With the addition of optimum diver- sity, the M-ary orthogonal code performs moderately better than uncoded signalling, but it is clearly not a very strong code for worst case partial-band noise. The (7,3) Trumpis code with diversity is clearly superior (about 4 dB better than the uncoded case at Pb = 10-5). Coding Countermeasures WC PARTIAL-BAND NOISE OPTIMUM DIVERSITY DUAL - 4, RATE 1/2 CONVOLUTIONAL CODE DUAL -4, RATE 1/3 CONVOLUTIONAL CODE 16-ARY ORTHOGONAL CONVOLUTIONAL CODE UNCODED Eb/N,,BB Figure 2.90. Same as Figure 2.87, but for K = 4. The dual-4 convolutional codes (both rates) perform about 3 dB better than uncoded signalling with optimum diver- sity at Pb = 10-5. WC PARTIAL- BAND NOISE OPTIMUM DIVERSITY DUAL-5, RATE 1/2 CONVOLUTIONAL DUAL-5, RATE 1/3 CONVOLUTIONAL CODE UNCODED 32-ARY ORTHOGONAL CONVOLUTIONAL CODE Eb/N,,BB Figure 2.91. Same as Figure 2.87, but for K=5. With optimum diversity, the orthog- onal convolutional code is about 1 dB better than uncoded signalling at Pb = 10-5. while the dual-K codes provide another 2 dB improvement. Non-Coherent Frequency-Hopped Systems WCn=1 BAND MULTITONE OPTIMUM DIVERSITY DUAL-I, RATE 1/2 CONVOLUTIONAL DUAL-1, RATE 1/3 CONVOLUTIONAL CODE UNCODED (7,1/3) BINARY (7, I/2) BINARY CONVOLUTIONAL CONVOLUTION- AL CODE Eb/Nj, dB Figure 2.92. Performance of several uncoded and convolutionally coded FH/binary FSK systems with 