Implementation of a Fast Frequency Hopping Spread Spectrum modulator with System Generator on a FPGA

This work is based on a previous FFHSS (Fast Frequency Hopping Spread Spectrum) transceiver designed for wireless optical communications. The core of the transmitter is a discrete DDS (Direct Digital Synthesizer). In the first prototype the DDS control and the digital synchronization signal were generated using a PLD (Programmable Logic Device), besides a discrete external filter was necessary to eliminate high frequency components of digital synchronization signal and generated analog synchronization signal. The FFHSS and analog synchronization signals were emitted by two separated optical devices to avoid adding them with discrete analog circuits. The objective of this work is redesign the modulator over a FPGA (Field Programmable Gate Array) using System Generator from Xilinx and analyse the performances of this design methodology. Key-Words: spread spectrum, modulator, System Generator, Xilinx, Simulink, FPGA, VHDL, floating point, fixed point.