Design of a slow frequency hopped radio modem

In this paper a slow frequency hopped radio modem is designed for use in a licence-free frequency band (known as the ISM band). The design emphasis is on the hopped frequency synchronization. To evaluate the performance, a frequency hopped system is set up using the software package SPW allowing the consideration of various forms of interference. Implementation using DSP chips is also conducted. Testing has shown that this modem is very practical for commercial use and can be used as mobile modem in a multiple access system with the existence of multipath fading and other interference.<>