An Adaptive Frequency Hopping System Based on the Detection of Spectrum Holes

Frequency hopping (FH) which can hop according to predefined frequency map becomes more and more important in the communications. However if it uses some frequencies which have been interfered, its performance will become worse. This affects communications quality. A new technique, named Spectrum hole detection technique, which is in cognitive radio, is proposed in this paper. And also an AFH system based on the spectrum holes detection technique is modeled and simulated in industrial scientific and medical(ISM) band. The new technique can identify the frequencies in use and unused precisely in ISM band. This avoids FH system using the frequencies which have been interfered and improves the communication quality. Simulation results have demonstrated its effectiveness in detection spectrum holes in the ISM band and shown the bit error rate (BER) performance of the proposed AFH system is improved evidently.