A/D Converter Clipping Noise Suppression for High-Sensitivity Carrier-Sensing of Cognitive Radio Transceiver

A technique for suppressing the clipping noise of an analogue to digital converter (ADC) is proposed to achieve the high-sensitivity carrier-sensing of a cognitive radio transceiver. When a large bandwidth cognitive radio transceiver performs carrier-sensing, it must receive a radio wave that includes many primary user transmissions. The radio wave may have high peak to average power ratio and clipping noise may be generated. Clipping noise becomes an obstacle to the achievement of high- sensitivity carrier-sensing In the proposed technique, the original values of the samples clipped by an ADC are estimated by interpolation. Polynomial spline interpolation to the clipped signal is performed in the first step, and then SINC function interpolation is applied to the spline interpolated signal. The performance was evaluated and about 20 dB suppression of clipping noise was achieved with the medium degree of clipping.