多序列跳频系统及其在AWGN信道下误码率性能分析

常规跳频系统发送的调制信号易被干扰损伤。本文提出一种新的多序列跳频系统，无需对载波进行调制，数据分组从一簇相互正交的跳频序列中选出某一跳频序列，该跳频序列的当前频率由射频端直接发送。相比差分跳频，多序列跳频的发送频率不仅是用户数据的函数，也是跳频序列的函数，增加了对发送频率的约束，因此可以采用窄带接收，更好地抑制了带外干扰。在AWGN信道下简要讨论了多序列跳频抗跟踪干扰性能，重点分析了其抗部分频带干扰性能。计算和仿真表明，多序列跳频受跟踪干扰影响不大；最坏部分频带干扰下，误码率为10^-5要求的信干比，MSFH比DFH低约1.5dB，比常规跳频低约2.5dB。 

Multi-Sequence Frequency Hopping System and Its BER Performance Analysis over AWGN Channel

The modulated signal in conventional frequency hopping (FH) system is vulnerable to jammings. In this paper, a novel FH system, the multi-sequence frequency hopping (MSFH) was introduced. In MSFH, a bits block selected a hopping pattern from a bunch of orthogonal hopping patterns, and a carrier at the current frequency of this pattern was transmitted directly without any modulation. Compared with the differential frequency hopping (DFH) system, the frequency used in MSFH was constrained more tightly not only by the data transmitted, but also by the hopping patterns. By this term a narrow band receiver was applicable, so the structure of the system could be simpler and reject the out-band jamming more efficiently. Its BER performance over AWGN channel was examined explicitly with partial band jamming and briefly with follower jamming. Calculation and simulation indicates that, MSFH is almost not influenced by the follower jamming. When the BER is under the worst-case partial band jamming, MSFH requires signal-to-jamming ratio (SJR) of 1.5dB less than the conventional FH and 2.5dB less than the DFH symbol-by-symbol (SBS) detector.