Design and implementation of Frequency Hopping Spread Spectrum (FHSS) system using FPGA

Abstract: Frequency hopping techniques are used in CDMA communication systems, where several hopping frequencies are allocated for each user within a specific frequency range for all users. The number of frequencies within a certain frequency range is fixed so that the interference noise is reduced.The frequency hopping algorithm for these frequencies varies from one user to another. In this paper, we propose a practical method for a frequency hopping system using a programmable hopping algorithm stored in ROM for the case of slow FHSS and fast FHSS, and for three users and eight frequencies , this system is designed using a cyclone II EP2C20F484C7 FPGA from ALTERA placed on education and development board DE-1 with the following parameters: -Clock frequency: FCLK=50MHz -Modulation type of signal is : 2FSK. -Frequency range: (0.011 Hz…10 MHz). -Frequency Resolution: (0.011 Hz). -Signal amplitude (5V). -Controlled parameters: values of hopping frequency, number of hopping frequencies, type of FHSS . -Update capability: changing hopping frequency algorithm, changing modulation type: BPSK, MFSK, increase frequency range up to 20MHz , changing data frequency and hopping frequency.

Keywords: FHSS, CDMA , FSK, FPGA, DDFS, SFHSS, FFHSS.