The Technology Of Adaptive ALE In The Short-ware-FH System

The short wave wireless communications has been widely used in middle and long distance communications domain for both military and civilian usages because it is characterized by good damage-resistance, simple structure, functional agility and low cost, especially the realization in stadia communications. The antenna transmission of the short wave communications depends mainly on the ionosphere reflection. However, since the ionosphere is a variable dispersive channel, its negative effect of instable transmission has to be overcome by complex manual operation for a long time, which limits further application of short wave radio.The appearance of adaptive short wave system characterized by line-foundation and channel estimation automatization has dramatically developed and improved the short wave communications technology, which makes communications more reliable and operative.The main research in this thesis is to discuss the statistic features and mathematical model (Watterson model) of the short wave channel by analyzing its transmission physical characteristics, and then set up its simulation model by software tools. Based on the understanding of the operation flow and principleof the FH system, the system model in short wave channel is established with MATLAB and the performance difference in noise-resistance ability between the common FH system and the 8FSK system is compared finally.