Sensing Window Length Optimization in Low-SNR Regime
For non-coherent detection based cognitive radio (CR), the required length of the spectrum sensing window is inversely proportional to the primary user’s (PUs) signal strength. When a CR system’s transmission period is fixed, the length of the CR’s transmission window can be inadequate to fully utilize the white space if the corresponding PUs operate in low-SNR regime. We propose a sensing window optimization algorithm in this paper aiming at improving the spectral efficiency of the cognitive Ultra Wideband (UWB) radio system. The proposed algorithm can find the optimal tradeoff between the sensing window length and the desired detection probabilities for the UWB based CR system in low-SNR regime. Compared with the conventional sensing algorithms in which the sensing window is fixed, the proposed algorithm can significantly increase the length of the CR-UWB’s transmission window so as to use the available spectrum more efficiently while guaranteeing the PUs’ operation.
KeywordsSpectrum sensing window Cognitive radio Ultra wideband Low-SNR regime
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