超窄带通信关键技术研究

THE STUDY OF CRITICAL TECHNOLOGY ABOUT UNB COMMUNICATION

本文首先介绍了超窄带通信中的关键技术——具有高频带利用率的双向编码调制方式：可变相移键控（VPSK）和甚小频移键控（VMSK）。在此基础上重点讨论了1／2甚小频移键控（VMSK／2）调制方式的编解码原理，并给出了其频谱的数学表达式和计算机仿真频谱图。对VPSK、VMSK及VMSK／2信号的频谱利用率作出初步估计，给出了VMSK／2射频传输系统设计方案。

Methods of biphase coded modulation with high spectral efficiency called Variable Phase Shift Keying（VPSK） and Very Minimum Shift Keying（VMSK）, which is used in UNB, were introduced firstly in this paper. Based on that the paper focused on 1/2Very Minimum Shift Keying（1/2VMSK）, described the principle of code modulation, presented a mathematical expression of the spectrum of these base band signals and showed some frequency spectrum obtained from computer simulation. The authors calculated the spectral efficiency of VPSK, VMSK, VMSK/2 and gave the design scheme of RF transmission system of VMSK/2.