Competent Realization of Co-Operative Spectrum Sensing in Cognitive Radio Systems

Cognitive radio is widely expected to be the next Big Bang in field of wireless communications. The objective of cognitive radio is to enhance the spectrum utilization efficiency. Spectrum sensing, a challenging task of cognitive radio helps in opportunistic spectrum access. Co-operative spectrum sensing mitigates these effects of fading, shadowing and uncertainties in normal sensing at the cost of energy consumption. Energy consumption in Co- operative spectrum sensing is due to computation of full spectrum FFT. This paper aims at the design of co-operative spectrum sensing unit in a cognitive radio system. It present a coprocessor for computing reduced point FFT, a block for the detection of spectrum hole, a fusion center for combining the decision from different users and a special prediction block for improving performance of Co-operative spectrum sensing. This idea reduces the computation to one fourth. The simulations are done using Xilinx ISE design suit 12.1 and ModelSim and synthesized using VerilogHDL.