多序列跳频系统及其在瑞利衰落信道下性能分析

差分跳频中，用户数据对频率选择的约束性比较弱。对此本文提出多序列跳频（MSFH）系统，其发送频率不仅是用户数据的函数，也受同步跳频序列严格约束，因此可以采用窄带接收更好地抑制带外干扰。具体地，数据分组从一簇相互正交的跳频序列中选出一个序列，该序列的当前频率由射频端直接发送，而无需对发送信号进行调制。得到了瑞利衰落信道中，未编码和采用卷积编码-硬/软判决Viterbi译码时MSFH符号误码率性能。计算和仿真表明，在相同编码增益下，MSFH误码率低于常规跳频系统；与差分跳频译码复杂度相当时，MSFH性能亦具有一定优势。 

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.