Design and development of a frequency hopper based on the DECT system for the 902-928 MHz ISM band

The Digital European Cordless Telecommunications (DECT) standard defines a high-performance digital communications system for two-way transfer of speech and data information. This thesis is concerned with the development of a frequency hopping Spread spectrum transceiver based on the DECT radio frequency (RF) front end, and fully compliant with FCC Part 15 rules for transmissions in the 902-928 MHz ISM band. A theoretical design of a slow frequency hopper (SFH) based on an existing DECT RF front end and a custom-designed system controller was developed. An innovative FH synchronization technique that eliminates the need for a separate FH tracking loop and can be implemented completely at baseband was designed. The practicality of the design was verified through extensive simulations. The SFH design was then implemented in prototype hardware using a digital signal processor acting as the system controller and using the DECT RF front end. Results show that the existing DECT physical layer can be successfully modified for spread spectrum transmissions in the ISM band fully compliant with FCC regulations.