A frequency transition function construction method of differential frequency hopping system

The differential frequency hopping (DFH) system brings a new technology for reliable high rate HF data transmission. DFH is the key technique of the correlated hopping enhanced spread spectrum (CHESS) radio. The core of DFH is the frequency transition function (FTF), which generates the FH pattern along with source data. This paper deduces and sums up the principle and optimizing objective of constructing the FTF according to the characteristics of a DFH system. Also, a type of effective construction method is put forward. This type of FTF is easy to generate with a key. The performance improvement of DFH communication systems obtained by this kind of FTF is analyzed in theory and with simulation. The numerical results show that this method, whose FH pattern has better randomicity and uniformity, is a benefit to the bit error rate (BER) of DFH communications system.