Diversity Combining Of Fast Frequency Hopping Systems And Algorithms,

The Frequency Hopping Communication which has been one of spread spectrum Communication technologies holds an excellent ability of anti-jamming, anti-fading. Especially the Fast Frequency Hopping technology which has become an important point in Frequency Hopping Communication research can highly improve the ability of anti-jamming and anti-fading of Frequency Hopping Communication. As being a crucial technology in Frequency Hopping Communication system, the study of diversity and combining technology became a serious technology problem to solve.This paper focus on studying the performance of diversity and combining technology of Fast Frequency Hopping Communication system in some typical jamming and fading channels, and based on two kinds of present algorithms, improving the threshold combining ,that comes to the Adjective Threshold Combining algorithm which was proved to have better performance than the previous algorithms.This paper has six Chapters. In chapter one, gives a brief introduction of Frequency Hopping Communication Systems. Chapters two, introduces the basic theory of diversity and combining technology, and then gives some basic models of several typical diversity and combining algorithms. In Chapter three, gives some simulations and comparisons between the classical diversity and combining algorithm in different communication jamming and fading channels.The improvements of this paper is mainly in chapter four, based on soft threshold decision combining and adjective gain control, introduce a better combining algorithm- Adjective Threshold Combining which could improve the ability of anti-jamming, anti-fading. Then gives some relational simulations'results and analysisChapter five, study on the performance of modulation and diversity of Frequency Hopping Communication systems in different jamming and fading channels. Then give some experimental simulations'results and analysis. In the last chapter some conclusions to the whole dissertation is given, and further research issues and possible research directions are pointed out.