Coding for slow frequency hopped differential phase shift keying

Abstract

The performance of Reed-Solomon (RS) error-correcting codes with slow frequency hopped (SFH) differential phase shift keying (DPSK) signaling is analyzed and evaluated under worst-case partial-band noise (PBN) and worst-case multitone jamming. The results of a study of the bit error rate (BER) performance of this coded system are presented. A representative set of the performance curves is shown. SFH is used because the differential signaling required only the phase of the previous received signal as a reference. Using DPSK eliminates the need to establish a phase reference for the hop, as with coherent signaling. From the results it is clear that the number of codeword symbols per hop must be small in order for the RS code to provide protection against jamming. Otherwise, no improvement over uncoded DPSK is gained. Lowering the symbols per hop can be achieved either by reducing the number of bits per hop, or interleaving the RS codewords to a depth determined by the hop length and RS code parameters. >