A real-time FPGA implementation of spectrum sensing applying for DVB-T primary signal

Spectrum sensing (SS) plays a significant role in cognitive radio network. In our work, we focused on FPGA (Field Programmable Gate Array) implementation of SS applying for DVB-T (Digital Video Broadcasting — Terrestrial) signal detection because TV band has been considered for the operation of cognitive users (unlicensed users) by Federal Communications Commission (FCC). The OFDM signal (Orthogonal Frequency Division Multiplexing) — 1024 subcarriers in 2k mode of DVB-T system is considered as primary transmitter as specified in IEEE 802.22 WRAN standard for reusing the TV frequency band. The system is synthesized and implemented on Stratix II EP2S180 board. The fixed point 32 bits (fraction: 22.10) is chosen for calculation in FPGA model. Numerical results showed that detection effectiveness of ED based on FPGA platform matched well with theoretical analyses. They also indicated that system performances degraded dramatically in Rayleigh fading environment. Thus, longer sensing time should be considered and and higher probability of false alarm should be accepted to improve sensing efficiency in fading condition.