In this paper, we propose a simple but effective way of improving the performance of channel estimation and catching the noise variance for pilot cyclic prefixed single carrier (PCP-SC) system. The proposed method utilizes the property that the shift of the PCP pilot signal can also be utilized to catch the channel information as a new pilot. Regardless of the signal-to-noise ratio (SNR) and the pilot type, the proposed method can achieve about a 1.72 dB performance gain for the mean squared error (MSE) of channel estimation with slightly additional computational complexity. In addition, regardless of the pilot type, the receiver can generate a new random signal from the pilot signal. The new signal has an identical variance value to that of the mixed AWGN noise. The proposed estimation method for noise variance is independent of channel estimation errors. Therefore it simplifies the receiver design and improves the system performance.