Performance Comparison of Dual-k Codes with FH/MFSK in AWGN, Rayleigh Fading and Fraction-of-Band Multitone Interference

Dual-k convolutional codes are codes in the alphabet of M = 2^k that provide good performance when used with M-ary signaling and soft-decision Viterbi decoding. The purpose of this paper is to consider Dual-k codes applied to frequency hopping (FH) communication systems using M-ary FSK channel modulation. The bit error rate performance (upper bound) is evaluated and compared for several alphabets (values of k) and a range of code rates. This is done for a selection of channels, including nonfading and Rayleigh fading in additive white Gaussian noise (AWGN), and fraction-of-the-band multitone interference. The performance is based on noncoherent square-law detection followed by soft-decision Viterbi decoding. The results should be an aid to performance/complexity trade-offs for such coded systems that must operate in the environments considered.