Multi-Sequence Frequency Hopping System and its Performance over Rayleigh Fading Channel

In the differential frequency hopping (DFH) system, the frequency selection process was constrained by information data in an actually loose way. To improve this, an innovative frequency hopping scheme, the multi-sequence frequency hopping (MSFH) was proposed. In MSFH, the transmitted frequency was constrained not only by the information data, but also strictly by the synchronized hopping patterns. By this means a narrow band receiver was applicable, so the system could reject the out-band jamming more efficiently. Specifically, in MSFH, a bit block selected a hopping pattern from a bunch of orthogonal hopping patterns, and a sinusoidal wave at the current frequency of this pattern was transmitted directly without modulation. The sign error rate (SER) performances of MSFH with no coding and with convolutional coding and hard/soft Viterbi decoding were investigated over Rayleigh fading channels. Calculation and simulation indicate that, the MSFH has lower SER versus the conventional FH-2FSK under the same coding gain, and it also outperforms the DFH of a comparable decoding complexity.