FPGA implementation of spectrum sensing based on energy detection for Cognitive Radio

Abstract

Spectrum sensing is a critical component of the Cognitive Radio that detects the presence of primary user signal in a channel. In this paper energy detection technique based on Neyman-pearson criterion is used to detect the presence of deterministic primary user (PU) signals in the channel. We have considered three different kinds of modulated signal such as BPSK, QPSK, DVB-T (2K mode) under additive white Gaussian noise (AWGN) and Rayleigh fading channel environment as specified in IEEE 802.22 standard for validating the algorithm. The simulation result shows that the energy detector achieves the desired probability of detection (≥0.9) with probability of false alarm (≤0.1) at low signal to noise ratio (SNR) up to −8dB for QPSK and DVB-T modulated signal with sample size of 64. The algorithm is also implemented in Xilinx Virtex2pro XC2VP30 (FFG896-7) Field Programmable Gate Array (FPGA). Hardware in loop (HIL) technique is used for verifying the algorithm in FPGA. The implementation result reveals that the algorithm fits into the Virtex2pro FPGA and can execute with operating frequency between 110 to 138 MHz for different sample size of primary user signals.