A WEIGHTED HARD COMBINATION SCHEME FOR COOPERATIVE SPECTRUM SENSING

Abstract

Ever increasing demand for the radio spectrum, provides the necessity for the innovation of the new techniques to sense the spectrum. Although, soft sensing method performs better in sensing the spectrum, due to the practicality limitations it has not been preferred in networks where there is a need for transferring of bits over a large area. To overcome the shortcomings of the conventional methods such as soft Combination (SC), Hard Combination (HC), and Quantize Combination (QC), a new method has been proposed in this paper. The proposed weighted hard Combination (WHC), conglomerates the benefits of both hard combination and quantize combination. The proposed WHC method has been discussed and the performance of this method is compared with the conventional methods such as QC and HC. The results reveal that the proposed WHC method clearly outperforms the Quantized combination in Primary User (PU) detection by 6 %. The Sensitivity of the WHC scheme is tested with certain variables such as number of secondary users and the SNR. A new Weighted MRC method is proposed by combining the WHC and MRC methods. The ROC curves and the sensitivity analysis of this method is simulated, and the new method clearly outperformed the Soft Combination and the WHC method.