Research On Frequency-Hopping Technique In Spectrum Spread Communication Systems

Spread-spectrum technique is a kind of technology of information transmission. It spreads the spectrum by using the pseudorandom code and makes its bandwidth much wider than the minimum bandwidth. Frequency-hopping (FH) technique has high ability of anti-interference and anti-fading. As a result, it has been widely used to prevent and reduce interference in the field of tactics communications. This thesis studied the Frequency-hopping technique in spectrum spread communication systems, and the main work included:1. The basic principles, the working modes and the advantages of the spectrum spread systems are introduced. Under typical interference, bit-error-rate (BER) performance analysis of FH/MFSK system is also presented.2. The FH pattern design and synchronization in FH system are mentioned. From the view of practice, the appropriate synchronization scheme is given in this thesis.3. Searching and realization of the pseudorandom code are studied. Especially, the keys and the difficulties of pseudorandom code searching are simulated and analyzed using Matlab, which includes query of excellence sequence,seeking for the eigenphasic of m-sequence, and search for balance Gold code.4. Theoretical analysis and simulation of FH/2FSK system are given in this thesis, including full-band interference and partial-band interference.5. Simulation model of FH communication system is built based on the Matlab/Simulink, and the results are shown using GUI tools.