Frequency-Hop Antijam Communications with Nonbinary Error-Control Coding

Abstract

Reed-Solomon codes are nonbinary error-control codes that have been employed in military frequency-hop spread-spectrum systems to mitigate the effects of partial-band jamming and other frequency-selective disturbances. Hermitian codes, which are also nonbinary codes, have been suggested as alternatives because they have longer block lengths for the same alphabet size. More recently, construction methods and efficient iterative decoding techniques have been developed for nonbinary quasi-cyclic low-density parity-check (LDPC) codes. For channels in which the only disturbance is thermal noise, nonbinary quasi-cyclic LDPC codes with iterative decoding have been shown to be superior to Reed-Solomon codes of the same block length. We compare the performance of LDPC, Hermitian, and Reed-Solomon codes for frequency-hop transmission over channels with partial-band jamming. Performance results are also included for interleaved binary product codes with iterative decoding. Comparisons are made for nonbinary orthogonal modulation with coherent and noncoherent demodulation.